No, I don't think. If they're data-mining against, say, what conferences you attend to see what adverts to show you, I seriously doubt that they're differentiating paid and unpaid users.
I disagree. If someone is providing a free app, it's essentially a honeypot. For what? Who knows.
Contrast with paid apps such as instagram or evernote or 37 signals: their business is to charge money. They have no interest in selling data because their customers won't like it, and you get probably an order of magnitude less money for data than by just charging for a product.
