It gets elaborate but you can essentially buy email address -> cookie mappings or make your own. You then sync those cookies with the ad exchange and then they're returned to you with every ad auction for that user.
I used to work for an ad retargeting company. Our advertisers gave us a ton of data that we didn't necessarily want along with pixel data that we did, including email addresses. So if you're logged in to some retailers website and they were retargeting with us, they might either accidentally or deliberately passing us your email address, which would allow us (if we wanted to) to map your email address to your cookie. We see your cookie look at galleries, bam.
Or, more legally, the advertisers could be part of a specific email retargeting campaign where they give us your email addresses, and then we can establish the mapping in a more direct way.
Obviously there must have been more shading goings on in this case, but the principle is the same.
Cookie onboarding services are nothing new. To start, look at a company like LiveRamp. They ask sites that get users to authenticate to login, then you provide them with an anonymous hashed email address of the user which they match with they then use to match against a larger cookie pool. If there's a match, they set another cookie.
This helps solve the issue for advertisers using retargeting where cookies don't have a long shelf life. So they leverage 2nd party data sources to basically set those cookies again for them so they can continue retargeting.
They can also work with vendors to upload their hashed email lists from their CRMs and gain access to the relevant cookies in the pool to market to them.
Onboarding vendors like this tend to pay a CPM rate based on the number of matches they can make with their cookie pool, so really all that matters is that you have a massive number of people authenticating with email addresses.
Canada|10 years ago
thatswrong0|10 years ago
Or, more legally, the advertisers could be part of a specific email retargeting campaign where they give us your email addresses, and then we can establish the mapping in a more direct way.
Obviously there must have been more shading goings on in this case, but the principle is the same.
shostack|10 years ago
This helps solve the issue for advertisers using retargeting where cookies don't have a long shelf life. So they leverage 2nd party data sources to basically set those cookies again for them so they can continue retargeting.
They can also work with vendors to upload their hashed email lists from their CRMs and gain access to the relevant cookies in the pool to market to them.
Onboarding vendors like this tend to pay a CPM rate based on the number of matches they can make with their cookie pool, so really all that matters is that you have a massive number of people authenticating with email addresses.
AndyMcConachie|10 years ago
Once you have the email addresses(see unshift's comment above) you upload them to Google and then target the addresses with specific ads.