Does this count as cheating the system?

I heard that you can have multiple games open and still get your trading card drops for all the games, so umm, I sorta just.... did this....

UPDATE: After about 20 minutes of idling I have already gotten four drops from a random handful of the games I'm idling. I don't know if there's a drop ratereduction, but if there is, it can't be too bad.

UPDATE 2: It's been another 30 minutes and I haven't gotten a single additional drop after the first four. I think I hit a glass ceiling...