Even jobs at places like target, kmart , toys r us and grocery stores require criminal background checks. Which means if the require it they know. And of they have a choice between someone that's got a criminal record and someone that doesn't they're not going to chose the one that does. Oh and you'll be required to have a background check torrent an apartment or house too.
You can also get the folder sealed. Convictions are bad if you want a good paying job. Can even affect relationships if your gf/bf checks your records (Which is wise for people to do by how many people lie these days, best to know what your getting into).