Personally, I choose to make that trade only with Google. One company has my profile, and in exchange I get many services.
You can't really be that naive are you? When Google has your data, Google's business partners have it too (part or parcel), the law can have it through subpoenas, the NSA... just about everybody.
Besides, I suspect Google uses the data in ways I don't want it to be used. So even if it was the sole guardian of it, I don't want to give it to them. Not willingly anyway, and as little as possible when I don't have the choice - and people have less and less choice as days go by in the matter.