[jesseryoung]

Fascinating. Any clue as to what the largest factor for "similarity" is, and how much it contributes?

[dalbasal]

These tweets are a pretty decent sample, though I suspect these factors (association with other phones/users and such) are more active in bid optimisation than list generation. Hands off stuff is gradually overtaking the "hand coded" elements. These, I imagine, can take advantage of wider set of heuristics.

List generation is dumber, and feels more hand coded. Basic demographics, facebook/instagram interests.