Post View Conversions

Limitations of IG Based Target/Trigger Solution

It's worth discussing some potential limitations with the approach laid out in this section, based on using IGs and auctions to join AuctionTargets and ConversionTriggers:

• IGs are expired after 30 days without a user-visit-based refresh (updateUrl won't do it), so conversion windows longer than 30 days won't be supportable with this technique.
• Privacy Sandbox APIs Disabled: in the case of a user turning off PS APIs, this won't work. For post-view in particular this is no different than a user disabling 3PC today.
• IG Limits: there are IG creation limits we could potentially run into:
  • 2000 IG limit per owner, where owner is defined by origin (i.e. conversions.pst.com is a different owner than www.pst.com. This seems the biggest limitation. We can have these not intrude on "data IGs" by having a different owner for them (conversions. vs ib.), so the issue would be if we had more 2000 AuctionTargets we needed to keep track of in a given browser. If we wanted to track all events that might lead to a conversion this would be problematic...I think what we'll want to do is track this way only for post-view (handle post-click with click ID), and may want to only keep the last AuctionTrigger IG per pixel (which would make it easy to leave and keep storage clean) or maybe the last 3 or so (could still clean that as well). That said, some analysis of how impactful this limitation will be would be valuable.
  • 1000 IG Owners per browser, meaning in theory we could be "locked out" of creating IGs if we are the 1001'st owner to create an IG. Probably unlikely...
• The DSP will need to allow the SSPs clients to create IGs for them. Doing this in a "secure" way will need some thought, as the functionally easiest way (which is used here) is that the DSP allows IG creation from anywhere on the internet, which will likely not be acceptable in the long run. (This of course matters less if the DSP and SSP are the same entity, since the "DSP" and "SSP" clients are easier to have use the same policy).