I've been collecting them since the last big Steam sale during Christmas. I don't know why I care about them, but those Steam badges and levels seem to scratch a collecting bug. I'm currently sitting at level 20.
I have a lot of games that have trading card drops, but I haven't had the effort/time to play them. Every so often, I'll install one, and let it run overnight to get the cards. I've been selling the doubles on the Steam Market, and using the funds to make complete sets.
I haven't crafted any badges since Christmas. I noticed that bonuses came with creating badges during the sale, so I think I'll wait until the summer sale to craft a bunch of badges.
If other RSers are collecting, I'll start saving my doubles for trades
