Originally Posted by AdultKing

None of these are really free.

Thunderbird is a product of Mozilla Corporation which is a subsidiary of the Mozilla Foundation. Mozilla makes about $300 million from search revenues. It's also supported by donations. Just because you might not shell out any cash to use Thunderbird, you are paying for it in other ways.

Google Drive, Maps & Earth are not free. They are part of the Google ecosystem which makes most of it's money through advertising. However when you use Drive, Maps and Earth you are actually paying through your own data. You essentially become the product. Google sells usage data, demographic data and other kinds of data for various reasons but one of those reasons is so other companies can use that data to target you for their commercial gain.

Facebook is not free, with Facebook you are the product, your data is valuable and Facebook makes a lot of money from it. It's also ad supported and while you may say that you don't look at the ads, unwittingly they contribute to your buying decisions.

If a company gives you something then it expects something back. You might not make a direct payment for the service or product, but you are definitely paying for it.