If I mention something in a Gmail message - say, a new bicycle for Christmas - I'm bound to get served up ads for cycle sales. Then they follow me around online.
I really don't mind, actually, since I'm not paying to use the email and I happen to be looking for a new road bike. But like anyone who interacts with ads daily, I have to see whether what's on offer fits my plan. In the end, no one cares about your money more than you, right?
In the ever-evolving online world, there's a new adage that applies. If you pay for something, it's the product. But if it's free, guess what - you're the product.
Consider yourself monetised.
Let me explain. Just think of Facebook and all the bells and whistles there that you get to use for free - you don't need to pay to play in that sandbox. But as you tag your friends or post to their timelines, Facebook is selling your eyes to advertisers.