It happens to me most of the time. Some are even airdrops while some are bounties. Because of that, I do check my wallet from time to time to see if I have received any of such coins. But the issue is that, most of them are not trading so they just occupy space.
I have promoted so many projects in the past that I forgot some of them and only remember after checking my compiled spreadsheets or receiving them, but the worse thing is receiving these coins when they have no value, like what happen to OP, really time wasted for promoting these useless projects.