I was reading through a thread here---the one about the AA17 emergency landing at JFK--- and noticed pop-up ad at the bottom advertising "70% off business class to London.". (I get a lot of targeted ads on this site from shopping I have done, but I have never searched for Business Class fares to London because we always fly with AA or BA miles).

I clicked on the button out of curiosity, suspecting it to be one of those sketchy mileage brokers. And indeed it is---Alpha Flight Guru.

Why are they allowed to advertise here?