Marketing Buying Vs Renting a List

[Mark W Carpenter]

Hey, Bp, Me and another investor were discussing different ways that we market and I would love to find out from all of you that are marketing to find out what is your best R.O.I % on Renting a list or buying it. 
So basically if you buy the list put the investment in, or are you using a list broker who will rent the list to you? 

Thank you so much in advance looking forward to reading all the responses.