Predicting expansion directions for expandable content item environments

1. A computer-implemented method, comprising:

receiving expandable content item requests for publishers, each request specifying a publisher resource address of a publisher resource and a content item environment in the resource, the publisher resource address defined by a resource path that includes a domain name of the publisher;

for each content item request, providing request data for a prediction specifying an expansion direction for the content item environment based on position data for the resource and the content item environment, the request data specifying the publisher resource address of the resource and the content item environment in the resource;

for each prediction for which a successful prediction of a predicted expansion direction occurs, selecting an expandable content item having an expansion direction that is consistent with the predicted expansion direction;

for each prediction for which a successful prediction does not occur:

determining, from position data from a plurality of other resources each having a resource path that includes the domain name of the publisher, a prediction specifying an expansion direction for the content item environment; and

selecting an expandable content item having an expansion direction that is consistent with the predicted expansion direction; and

for each content item request, providing response data in response to the content item request that causes the selected expandable content item to be provided for the content item environment.

2. The method of claim 1 , wherein:

each prediction specifying an expansion direction comprises, for each of a plurality of expansion directions, a probability of expansion in the expansion direction; and

determining from prediction data for the plurality of other resources each having a resource path that includes the domain name of the publisher the prediction specifying the expansion direction for the content item environment comprises:

determining for each resource a probability of expansion for each expansion direction for the content item environment; and

determining for each expansion direction an estimated probability of expansion from the probabilities of expansion for the expansion direction for each resource.

3. The method of claim 2 , wherein determining for each expansion direction the estimated probability of expansion from the probabilities of expansion for the expansion direction for each resource comprises determining, for each expansion direction, a central tendency of the probabilities of expansion for the expansion direction.

4. The method of claim 1 , wherein:

determining from position data for the plurality of other resources each having a resource path that includes the domain name of the publisher the prediction specifying the expansion direction for the content item environment comprises:

for each of a plurality of expansion directions:

determining a number of observed expansions in the expansion direction for the content item environment for each resource;

summing the numbers of expansions in the expansion direction for the content item environment for each resource to generate a summed expansion number for the expansion direction; and

determining, from the summed expansion number for each expansion direction, the prediction specifying the expansion direction for the content item environment.

5. The method of claim 4 , wherein determining, from the summed expansion number for each expansion direction, the prediction specifying the expansion direction for the content item environment comprises selecting as a predicted expansion direction the expansion direction having a largest of the summed expansion numbers.

6. The method of claim 1 , wherein determining, from position data from a plurality of other resources each having a resource path that includes the domain name of the publisher, a prediction specifying an expansion direction for the content item environment comprises determining the prediction specifying the expansion direction only when a corresponding prediction likelihood meets a minimum likelihood threshold.

7. The method of claim 1 , wherein:

each of the other resources has a resource address that includes the domain name of the publisher, a path, and a resource name of resource, and wherein the path for each resource is the same.

8. The method of claim 1 , wherein:

each of the other resources has a resource address that includes the domain name of the publisher, a path, and a resource name of resource, and wherein at least two paths are specified.

9. The method of claim 1 , wherein the expandable content item is an expandable advertisement.

10. A system, comprising:

a data processing apparatus comprising on more processors; and

a non-transitory computer memory apparatus in data communication with the data processing apparatus and storing instructions executable by the data processing apparatus and that upon such execution cause the data processing apparatus to perform operations comprising:

receiving expandable content item requests for publishers, each request specifying a publisher resource address of a publisher resource and a content item environment in the resource, the publisher resource address defined by a resource path that includes a domain name of the publisher;

for each content item request, providing request data for a prediction specifying an expansion direction for the content item environment based on position data for the resource and the content item environment, the request data specifying the publisher resource address of the resource and the content item environment in the resource;

for each prediction for which a successful prediction of a predicted expansion direction occurs, selecting an expandable content item having an expansion direction that is consistent with the predicted expansion direction;

for each prediction for which a successful prediction does not occur:

determining, from position data from a plurality of other resources each having a resource path that includes the domain name of the publisher, a prediction specifying an expansion direction for the content item environment; and

selecting an expandable content item having an expansion direction that is consistent with the predicted expansion direction; and

for each content item request, providing response data in response to the content item request that causes the selected expandable content item to be provided for the content item environment.

11. The system of claim 10 , wherein:

each prediction specifying an expansion direction comprises, for each of a plurality of expansion directions, a probability of expansion in the expansion direction; and

determining from prediction data for the plurality of other resources each having a resource path that includes the domain name of the publisher the prediction specifying the expansion direction for the content item environment comprises:

determining for each resource a probability of expansion for each expansion direction for the content item environment; and

determining for each expansion direction an estimated probability of expansion from the probabilities of expansion for the expansion direction for each resource.

12. The system of claim 11 , wherein determining for each expansion direction the estimated probability of expansion from the probabilities of expansion for the expansion direction for each resource comprises determining, for each expansion direction, a central tendency of the probabilities of expansion for the expansion direction.

13. The system of claim 10 , wherein:

determining from position data for the plurality of other resources each having a resource path that includes the domain name of the publisher the prediction specifying the expansion direction for the content item environment comprises:

for each of a plurality of expansion directions:

determining a number of observed expansions in the expansion direction for the content item environment for each resource;

summing the numbers of expansions in the expansion direction for the content item environment for each resource to generate a summed expansion number for the expansion direction; and

determining, from the summed expansion number for each expansion direction, the prediction specifying the expansion direction for the content item environment.

14. The system of claim 13 , wherein determining, from the summed expansion number for each expansion direction, the prediction specifying the expansion direction for the content item environment comprises selecting as a predicted expansion direction the expansion direction having a largest of the summed expansion numbers.

15. The system of claim 10 , wherein determining, from position data from a plurality of other resources each having a resource path that includes the domain name of the publisher, a prediction specifying an expansion direction for the content item environment comprises determining the prediction specifying the expansion direction only when a corresponding prediction likelihood meets a minimum likelihood threshold.

16. The system of claim 10 , wherein:

each of the other resources has a resource address that includes the domain name of the publisher, a path, and a resource name of resource, and wherein the path for each resource is the same.

17. The system of claim 10 , wherein:

each of the other resources has a resource address that includes the domain name of the publisher, a path, and a resource name of resource, and wherein at least two paths are specified.

18. The system of claim 10 , wherein the expandable content item is an expandable advertisement.

19. A computer memory apparatus storing instructions executable by a data processing apparatus and that upon such execution cause the data processing apparatus to perform operations comprising:

receiving expandable content item requests for publishers, each request specifying a publisher resource address of a publisher resource and a content item environment in the resource, the publisher resource address defined by a resource path that includes a domain name of the publisher;

for each content item request, providing request data for a prediction specifying an expansion direction for the content item environment based on position data for the resource and the content item environment, the request data specifying the publisher resource address of the resource and the content item environment in the resource;

for each prediction for which a successful prediction of a predicted expansion direction occurs, selecting an expandable content item having an expansion direction that is consistent with the predicted expansion direction;

for each prediction for which a successful prediction does not occur:

determining, from position data from a plurality of other resources each having a resource path that includes the domain name of the publisher, a prediction specifying an expansion direction for the content item environment; and

selecting an expandable content item having an expansion direction that is consistent with the predicted expansion direction; and

for each content item request, providing response data in response to the content item request that causes the selected expandable content item to be provided for the content item environment.

20. The computer memory apparatus of claim 19 , wherein:

each prediction specifying an expansion direction comprises, for each of a plurality of expansion directions, a probability of expansion in the expansion direction; and

determining from prediction data for the plurality of other resources each having a resource path that includes the domain name of the publisher the prediction specifying the expansion direction for the content item environment comprises:

determining for each resource a probability of expansion for each expansion direction for the content item environment; and

determining for each expansion direction an estimated probability of expansion from the probabilities of expansion for the expansion direction for each resource.