Yea, I don't know why you would even question promos. They are good things for a regular for a couple reasons. You get something extra in return for what you were already doing... ie. 2x Points, Bonus $, Freerolls
to FTOPS, etc. Also, they bring more fish to the tables being one of the biggest, therefore you're able to capitalize off of them trying to capitalize off of a promo. I do this all of the time with the academy.
Example: Go into a micro stakes game and watch all of the players whose normal preflop raise is 3xBB from all positions, but then all of the sudden they min raise from EP or raise 2.5BB from MP. You can almost always be sure they are trying to complete the Pre-Flop Play challenge and they have a premium hand. It is a huge tell because once you notice that someone is on that challenge, you can beat the crap out of them. You'll also know that they can't open call, so if they open raise to their regular amount, you can easily push them off because you know it isn't premium, but it was a hand they would have liked to see a cheap flop for. Try watching for this and capitalize!