If I include a copyleft license on my GitHub repo for the app I'm building, what opportunities am I giving up?

I'm creating an app for web, android, and Pebble. It's just for personal use now, but I would like for others to be able to contribute if they want. And if they really like it, I think it's nice to let people fork it and build a unique version on top of the original. That being said, is including one of the listed licenses going to keep me from being able to take it to the next level and make money on it in the future? (assuming it gets to that point. but for now i just want to make sure i don't end up shooting myself in the foot)

Does all this mean that it can't ever be commercialized? I've read a ton of stuff all day today, but it would be nice if I could get an explanation in laymen's terms. All the technicalities are starting to blend together.