I hadn't realised that other people didn't know this, but, apparently, some of them didn't.
If you like something on Facebook (like a football team, or a kind of shoes, or a band), then when those people pay Facebook to advertise them, your liking of them will be used as the advert. It can be as simple as "Andrew Ducker likes Manchester United!", or if you wrote more, they'll use that.
It always annoys me when I see ads on my FB page, because they're almost always "Here are things your friends like!" - and I know that if my friends could resist the urge to tell Facebook that they like Pollock's Patented Urinals then I wouldn't get this repeated once a day, just in case I could be persuaded to take a look and then buy something from them.
And if you like something _and_ comment then you've just written them an advert. And then you end up
like this, used to sell things to people.
And this shouldn't surprise you - this is how Facebook make their money.
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