How exactly do property manager's make a profit?

[Jimmy Klein]

I'm looking at some turnkey properties. I see property managers charging just 8% of rent and thats not much considering rent can be less than a 1k a month. I also seen turnkey rentals where they even set up the LLC and do all the work for you. I just have a hard time believing $50-$100 a month in fees is really worth it for them.