Transmitting valid coupon offers to an email recipient

1. A computer-implemented method executed using a server computer, the method comprising:

receiving in real-time, from an email client, an indication that an email message was opened at a first time, wherein the email message was sent by an email server to a user account at a previous time;

determining in real-time a set of valid coupon offers for the user account among a plurality of user accounts;

transmitting the set of valid coupon offers in real time to the user account for insertion into the email message;

receiving an indication that the email message was opened at a second time subsequent to the first time;

determining if a difference between the second time and the first time exceeds a predetermined threshold; and if the difference between the second time and the first time exceeds the predetermined threshold:

determining in real-time and based on an update to transaction history or preference data associated with the user account, a second set of valid coupon offers for the user account, and

transmitting in real-time, the second set of valid coupon offers to the user account for insertion into the email message.

2. The method of claim 1 , wherein the transaction history associated with the user account includes one or more of: coupons stored to a loyalty account associated with the user, coupons redeemed by the user, and products purchased by the user account.

3. The method of claim 1 , wherein the preference data associated with the user account includes a preference for not receiving coupons for certain category of products.

4. The method of claim 1 , wherein determining the set of valid coupon offers comprises:

filtering a superset of valid coupon offers based at least on user eligibility criteria to determine the set of valid coupon offers.

5. The method of claim 4 , further comprising:

receiving, with the indication that the email message was opened at the first time, identification information for the user account; and

using the identification information to perform a lookup of a user account database in order to determine the user eligibility criteria.

6. The method of claim 4 , wherein determining the set of valid coupon offers comprises:

filtering the superset of valid coupon offers based at least on coupon campaign criteria to determine the set of valid coupon offers.

7. The method of claim 6 , further comprising:

receiving, with the indication that the email message was opened at the first time, identification information for a coupon campaign; and

using the identification information for the coupon campaign to perform a lookup of a coupon offer database in order to determine the coupon campaign criteria.

8. The method of claim 1 , wherein transmitting in real-time, the set of valid coupon offers to the user account for insertion into the email message comprises storing the set of the valid coupon offers in an offer cache.

9. The method of claim 8 , further comprising:

determining that at least one valid coupon offer of the set of the valid coupon offers has been selected, by performing a lookup of the offer cache.

10. The method of claim 8 , further comprising:

receiving an indication that the email message was opened at a second time subsequent to the first time;

performing a lookup of the offer cache to determine the set of valid coupon offers transmitted to the user account; and

transmitting the set of valid coupon offers to the user account for insertion into the email message.

11. One or more non-transitory computer-readable media storing instructions which, when executed by one or more processors, cause:

receiving in real-time, from an email client, an indication that a user has opened an email receiving in real-time, from an email client, an indication that an email message was opened at a first time, wherein the email message was sent by an email server to a user account at a previous time;

determining in real-time a set of valid coupon offers for the user account among a plurality of user accounts;

transmitting the set of valid coupon offers in real time to the user account for insertion into the email message;

receiving an indication that the email message was opened at a second time subsequent to the first time;

determining if a difference between the second time and the first time exceeds a predetermined threshold; and if the difference between the second time and the first time exceeds the predetermined threshold:

determining in real-time and based on an update to transaction history or preference data associated with the user account, a second set of valid coupon offers for the user account, and

transmitting in real-time, the second set of valid coupon offers to the user account for insertion into the email message.

12. The one or more non-transitory computer-readable media of claim 11 , wherein the transaction history associated with the user account includes one or more of: coupons stored to a loyalty account associated with the user, coupons redeemed by the user, and products purchased by the user account.

13. The one or more non-transitory computer-readable media of claim 11 , wherein the preference data associated with the user account includes a preference for not receiving coupons for certain category of products.

14. The one or more non-transitory computer-readable media of claim 11 , wherein determining the set of valid coupon offers comprises:

filtering a superset of valid coupon offers based at least on user eligibility criteria to determine the set of valid coupon offers.

15. The one or more non-transitory computer-readable media of claim 14 , further comprising instructions which, when executed by the one or more processors, cause:

receiving, with the indication that the email message was opened at the first time, identification information for the user account; and

using the identification information to perform a lookup of a user account database in order to determine the user eligibility criteria.

16. The one or more non-transitory computer-readable media of claim 14 , wherein determining the set of valid coupon offers comprises:

filtering the superset of valid coupon offers based at least on coupon campaign criteria to determine the set of valid coupon offers.

17. The one or more non-transitory computer-readable media of claim 16 , further comprising instructions which, when executed by the one or more processors, cause:

receiving, with the indication that the email message was opened at the first time, identification information for a coupon campaign; and

using the identification information for the coupon campaign to perform a lookup of a coupon offer database in order to determine the coupon campaign criteria.

18. The one or more non-transitory computer-readable media of claim 11 , wherein transmitting in real-time, the set of valid coupon offers to the user account for insertion into the email message comprises storing the set of the valid coupon offers in an offer cache.

19. The one or more non-transitory computer-readable media of claim 18 , further comprising instructions which, when executed by the one or more processors, cause:

determining that at least one valid coupon offer of the set of the valid coupon offers has been selected, by performing a lookup of the offer cache.

20. The one or more non-transitory computer-readable media of claim 18 , further comprising instructions which, when executed by the one or more processors, cause:

receiving an indication that the email message was opened at a second time subsequent to the first time;

performing a lookup of the offer cache to determine the set of valid coupon offers transmitted to the user account; and

transmitting the set of valid coupon offers to the user account for insertion into the email message.