So, what would a universal cookie across both Display and PPC give us?  What could we look forward to, what’s the wish list of the online “ideal marketing world” we could live in when we really understand how Display and PPC interact? 

I’ll give it a start, feel free to add to this wish list…

1.  From a macro web advertising perspective, all available Google-Click “space” is capable of being optimized for performance – whatever your definition of “performance” is.  That means an end to the idea of the space being attached to a pricing model – for any given space, you might see either a PPC ad or a Display ad. 

Hopefully, the advertiser would have some control over this allocation, deciding if / when which pricing models are used in which spaces, similar to the controls over pricing model existing in AdSense today.

I realize running Display units in Search inventory may seem counter-intuitive, but the key is pricing control.  The web desperately needs a more effective way to expose people to ideas they have never heard of in context.  Running random display units across opaque networks is not a particularly good way to do this; running targeted display units based on search history – a more advanced form of behavioral targeting – would do the trick.

Likewise, running PPC ads in tightly segmented display spaces can lead to big payoffs, as it did in the Lab Store example.

2.  A real gift would be some cookie-based sense of where the visitor is in the funnel, probably based on the search phrases they are using. 

“Level 1” would be no prior interest, “Level 2” would be “uses single word searches” on the topic, “Level 3” would be “uses multi-word phrases” on the topic, and so forth.  Visitors in the unknowing or shallow knowledge Levels would be exposed to cheap Display units – both in Search and in Display inventory.  Those expressing active interest (Engaged, if you will) would be exposed to PPC units, again, both in Search and in Display inventory.

You’d need some kind of history control on this, because the data set would probably get too huge.  Say for example, trailing 30 days interest, so you make sure the visitor is still Engaged with the topic.  As active searching on the topic dropped off, you’d kill the data off, because it’s no longer relevant.  If it starts up again, so be it, but a restart is a new profile.

Other ideas from the crowd?

Given cross-site tracking already exists for Display, do you think there will be any Privacy problems if Search History was used to target outside of Search?  People are pretty used to seeing ads based on searches in the search space…why not bring that over to Display?

Do you think Google-Click will give us a “universal cookie”, or will they keep the Display side in the dark for the sake of Brand-oriented folks who only care about impressions?