Just make sure it is done correctly, and you will be good. 

Asking in the correct forum will get a better response.Read the RULES!

Yes, there are bad areas and appreciation probably won't happen...but rents are not declining, there are great tenants if you screen correctly, and even the C neighborhoods generate great $.

If done correctly, it is for liability purposes.   

Asking in the correct forum will get a better response.Read the RULES!

Yes, a rule of thumb COULD eliminate a good deal if not applied correctly.

Good luck So this prompted me to do some research and @Dan H. is correct on things.

@Brandon Croucier That isn't correct... state laws allow you to enter the property within certain time periods, normally 24 hrs, with or without permission.

Usually FSBO listings (but there are other techniques).  

Denver Creative Housing, Denver Sublets, Roomies, Roommates, and so on, there are a few good ones)Also, I use Roomies as well because it is a site specific to finding roommate tenants, and there is a huge demand for it as well, so it is a great alternative to fill vacancies for houses if your owners are open to it and you price it correctly.