Google's data collection seems much more "transactional" to me. Most of what I share with Google seems to give me something in return, and I don't see obvious "leakage" of this information. Beyond whether or not my contacts have a gmail account or not, I know exactly nothing about what my contacts do with Google, or if they use it at all. I also don't see third party companies with information about me from Google. edit: I will say, I started to get skeeved out by Google when they were pushing Google+ hard, because they started having the same kinds of problems: information about contacts was popping up in places it didn't belong. It was never as bad as FB, but I'm still glad that failed.
In contrast, FB seems to just want everything, and they're much more subtle about how they get it. But worse than that, I constantly see information about friends and myself from FB in places that it didn't seemed like it belonged. Right from the very, very beginning: remember when websites would show you people that "liked" them, and your friends would be at the top? That kind of shit just screams "leakiness" and it's why even since 2005 or so I gave as little information to FB as possible.
FB's problem is that their business model requires them to exploit some users information to generate content for other users. They've been getting more and more aggressive about this over time. It used to just be your friends content, and people seemed OK with that. But as they pushed the limits further and further, it's getting too fucking weird and people don't like it.
Google isn't like this. Google shows me ads when I search for stuff about what I'm searching for. They show me ads in maps when I'm looking for places. That doesn't bother me. The FB equivalent would be telling me about my friends who also searched for this, or also went to this place (hell, FB does this, a perfect example of what I was saying above). If Google starts doing that kind of shit, that will be the end of Google for me.