Free Concert Tickets From Facebook?

[Hugo]

I am not a Facebook user, but I am able to answer your question. The reason why you're receiving unwanted notifications, such as Concerts, or other kind of events is because people who have created those events have an agreement with Facebook, Inc. That's how Facebook makes its profit, by advertising products and such. Facebook advertised products depending on the things that you like, for example: If you like fashion, Facebook will put ads on your page which will make you want to buy it, such as deals in order to sell you the product. This is how business operate.
Most of concerts Facebook notifies are legit, which means they are real. But, if a friend or a fanboy/girl decides to create an event, like saying their favorite artist will have a concert around the city and you're supposed to buy the tickets through her/his website, you wouldn't do it because that sounds like a fraud to me.