Methods and apparatus to collect distributed user information for media impressions and search terms

A method performed by a computing system comprising at least one processor and a memory, the method comprising:

• encrypting a first identifier based on a first encryption key corresponding to a first database proprietor, wherein the first database proprietor stores first user information associated with the first identifier, and wherein the first identifier identifies at least one of a media device or a user of the media device to the first database proprietor;
• encrypting a second identifier based on a second encryption key corresponding to a second database proprietor, wherein the second database proprietor stores second user information associated with the second identifier, and wherein the second identifier identifies the at least one of the media device or the user of the media device to the second database proprietor;
• transmitting, via a network and to a first server associated with the first database proprietor, a first network communication comprising the encrypted first identifier and an impression identifier, wherein the impression identifier identifies an impression event of online media presented at the media device;
• transmitting, via the network and to a second server associated with the second database proprietor, a second network communication comprising the encrypted second identifier and the impression identifier;
• and
• transmitting, via the network and to a third server, a third network communication comprising the impression identifier.

A system comprising:

• at least one processor;
• and
• memory comprising instructions that, when executed, cause the at least one processor to perform operations comprising:
• encrypting a first identifier based on a first encryption key corresponding to a first database proprietor, wherein the first database proprietor stores first user information associated with the first identifier, and wherein the first identifier identifies at least one of a media device or a user of the media device to the first database proprietor;
• encrypting a second identifier based on a second encryption key corresponding to a second database proprietor, wherein the second database proprietor stores second user information associated with the second identifier, and wherein the second identifier identifies the at least one of the media device or the user of the media device to the second database proprietor;
• transmitting, via a network and to a first server associated with the first database proprietor, a first network communication comprising the encrypted first identifier and an impression identifier, wherein the impression identifier identifies an impression event of online media presented at the media device;
• transmitting, via the network and to a second server associated with the second database proprietor, a second network communication comprising the encrypted second identifier and the impression identifier;
• and
• transmitting, via the network and to a third server, a third network communication comprising the impression identifier.