> 1) That kind of targeting is even less useful outside of FB. You can upload gmail addresses to Google to target, or use something like LiveRamp to target on display networks, but both options suck compared to FB.
Both google and FB are financially incentivized to provide as much granularity in targeting as possible so they can charge more money to advertisers, who'll get a better return and get promoted. All up until the point that it becomes a liability. Thats the line they're walking - you can totally target quite a few things that end up correlating to say, neurotic people, if you know your audience is neurotic people. You have enough of the dataset at that point.
Both google and FB are financially incentivized to provide as much granularity in targeting as possible so they can charge more money to advertisers, who'll get a better return and get promoted. All up until the point that it becomes a liability. Thats the line they're walking - you can totally target quite a few things that end up correlating to say, neurotic people, if you know your audience is neurotic people. You have enough of the dataset at that point.