Presenting content in accordance with a placement designation

1. A computer-implemented method comprising:

updating a user interface presented at a client device of a content sponsor to present a term specification control that enables the content sponsor to specify a campaign term for at least one content item that is presented to users responsive to requests for content;

receiving, through interaction with the term specification control, a given campaign term;

in response to receiving the given campaign term, updating the user interface to present: (i) the received campaign term along with a campaign term selection control, and (ii) a series of prefixes for the received campaign term along with a plurality of prefix selection controls, each prefix being associated with a respective prefix selection control;

receiving, by a content management system, through interaction with the campaign term selection control, a selection of the received campaign term;

in response to receiving the selection of the received campaign term, associating the selected campaign term with the at least one content item;

receiving, by the content management system, through interaction with one or more of the prefix selection controls, a selection of one or more prefixes for the received campaign term;

in response to receiving the selection of one or more prefixes for the received campaign term, storing campaign information identifying the one or more prefixes in association with the at least one content item;

determining that presentation of an inline search suggestion control at a user device has been triggered by entry of a partial form of a search string entered into a search control of a search interface presented at the user device;

receiving, by the content management system and through the search control of the search interface presented at the user device, a sequence of letters included in the partial form of the search string, as the sequence of letters are being entered into the search control of the search interface;

determining, by the content management system, that the received sequence of letters included in the partial form of the search string matches a selected prefix for the received campaign term, the selected prefix having been selected through interaction with its respective prefix selection control and having been stored in the campaign information in association with the at least one content item; and

dynamically updating the inline search suggestion control to include a presentation of the at least one content item in the inline search suggestion control, along with one or more search suggestions, wherein the dynamic update is performed in response to entry of the partial form of the search string and the determination that the entered partial form of the search string matches the selected prefix.

2. The computer-implemented method of claim 1 , wherein the campaign term is a word.

3. The computer-implemented method of claim 1 , wherein the campaign term is a phrase.

4. The computer-implemented method of claim 1 , further comprising updating the user interface presented at the client device of the campaign sponsor to present estimated reach information for the received campaign term.

5. The computer-implemented method of claim 1 , further comprising updating the user interface presented at the client device of the campaign sponsor to present estimated reach information for each of the prefixes.

6. The computer-implemented method of claim 1 , wherein the series of prefixes for the campaign term is presented in order according to a number of letters included in each prefix.

7. A non-transitory computer storage medium encoded with instructions that when executed by one or more computers cause the one or more computers to perform operations comprising:

updating a user interface presented at a client device of a content sponsor to present a term specification control that enables the content sponsor to specify a campaign term for at least one content item that is presented to users responsive to requests for content;

receiving, through interaction with the term specification control, a given campaign term;

in response to receiving the given campaign term, updating the user interface to present: (i) the received campaign term along with a campaign term selection control, and (ii) a series of prefixes for the received campaign term along with a plurality of prefix selection controls, each prefix being associated with a respective prefix selection control;

receiving, by a content management system, through interaction with the campaign term selection control, a selection of the received campaign term;

in response to receiving the selection of the received campaign term, associating the selected campaign term with the at least one content item;

receiving, by the content management system, through interaction with one or more of the prefix selection controls, a selection of one or more prefixes for the received campaign term;

in response to receiving the selection of one or more prefixes for the received campaign term, storing campaign information identifying the one or more prefixes in association with the at least one content item;

determining that presentation of an inline search suggestion control at a user device has been triggered by entry of a partial form of a search string entered into a search control of a search interface presented at the user device;

receiving, by the content management system and through the search control of the search interface presented at the user device, a sequence of letters included in the partial form of the search string, as the sequence of letters are being entered into the search control of the search interface;

determining, by the content management system, that the received sequence of letters included in the partial form of the search string matches a selected prefix for the received campaign term, the selected prefix having been selected through interaction with its respective prefix selection control and having been stored in the campaign information in association with the at least one content item; and

dynamically updating the inline search suggestion control to include a presentation of the at least one content item in the inline search suggestion control, along with one or more search suggestions, wherein the dynamic update is performed in response to entry of the partial form of the search string and the determination that the entered partial form of the search string matches the selected prefix.

8. The non-transitory computer storage medium of claim 7 , the operations further comprising updating the user interface presented at the client device of the campaign sponsor to present estimated reach information for the received campaign term.

9. The non-transitory computer storage medium of claim 7 , the operations further comprising updating the user interface presented at the client device of the campaign sponsor to present estimated reach information for each of the prefixes.

10. The non-transitory computer storage medium of claim 7 , wherein the series of prefixes for the campaign term is presented in order according to a number of letters included in each prefix.

11. A system comprising:

one or more processors; and

one or more memory elements including instructions that, when executed, cause the one or more processors to perform operations comprising:

updating a user interface presented at a client device of a content sponsor to present a term specification control that enables the content sponsor to specify a campaign term for at least one content item that is presented to users responsive to requests for content;

receiving, through interaction with the term specification control, a given campaign term;

in response to receiving the given campaign term, updating the user interface to present: (i) the received campaign term along with a campaign term selection control, and (ii) a series of prefixes for the received campaign term along with a plurality of prefix selection controls, each prefix being associated with a respective prefix selection control;

receiving, by a content management system, through interaction with the campaign term selection control, a selection of the received campaign term;

in response to receiving the selection of the received campaign term, associating the selected campaign term with the at least one content item;

receiving, by the content management system, through interaction with one or more of the prefix selection controls, a selection of one or more prefixes for the received campaign term;

in response to receiving the selection of one or more prefixes for the received campaign term, storing campaign information identifying the one or more prefixes in association with the at least one content item;

determining that presentation of an inline search suggestion control at a user device has been triggered by entry of a partial form of a search string entered into a search control of a search interface presented at the user device;

receiving, by the content management system and through the search control of the search interface presented at the user device, a sequence of letters included in the partial form of the search string, as the sequence of letters are being entered into the search control of the search interface;

determining, by the content management system, that the received sequence of letters included in the partial form of the search string matches a selected prefix for the received campaign term, the selected prefix having been selected through interaction with its respective prefix selection control and having been stored in the campaign information in association with the at least one content item; and

dynamically updating the inline search suggestion control to include a presentation of the at least one content item in the inline search suggestion control, along with one or more search suggestions, wherein the dynamic update is performed in response to entry of the partial form of the search string and the determination that the entered partial form of the search string matches the selected prefix.

12. The system of claim 11 , the operations further comprising updating the user interface presented at the client device of the campaign sponsor to present estimated reach information for the received campaign term.

13. The system of claim 11 , the operations further comprising updating the user interface presented at the client device of the campaign sponsor to present estimated reach information for each of the prefixes.

14. The system of claim 11 , wherein the series of prefixes for the campaign term is presented in order according to a number of letters included in each prefix.