Your market, the type of area, the actual location of the marketing, the frequency you are marketing, the timing of the marketing, competition's use of the technique, these all will play into how many calls you get from certain strategies.

I sent out 5 rounds to all 30 houses on a weekly frequency.

The probability of getting a positive ROI on direct mail will depend directly on factors such as quality of leads, frequency, consistency, mail piece, your phone skills, lead management, negotiation skills.......You see where I'm going with it.

Change your rent frequency.

I'm averaging a cost of 12 cents a touch this way and hitting a frequency of 9+.

Indianapolis is a great marketIf you're single without anybody to answer to you might want to just rent out a property and then rent out rooms like a four bedroom two bath house, live rent freeGetting a real estate license might be a good idea so that you can get some respect in the marketplace because people respect people that a licensedIf you doing just wholesaling it might take you a long time to make money, but if you have say 500 a month for six months you may very well get some deals; @Dev Horn writes often about marketing from the wholesaling deals in "the rule of seven " and frequency of direct-mailI think the fastest start for new people is to go after "expired listings" and talk to homesellers that have little equity that are pretty with no work needed; your job is to help them sell on terms verses for cash on the lease to own; Then you find a buyer that "just missed financing" and wants to "rent to own"You generally make a 3% assignment fee usually in 45 days; that's much faster than wholesaling and you don't to deal with builders or Hard Money lenders,  just the buyer and sellerI train on lease option assignments so see the free training on My BP blog Reiskills Best of luck!

It would be immensely helpful if anyone could enlighten me on what to expect on the subjects of fire, elevator and water tower inspections (frequency/cost), building maintenance, insurance, property management, etc.I believe 5% each month and a 2-3 month fee for finding tenants, please correct me if im wrong. 

How many letters did you mail, over what frequency, to how many addresses?

@Stuart Fox is right regarding the low quality of tenants and frequency of turnover costs may negate any Cash Flow benefits you may expect.  

Just look at the forum homepage to see the frequency with which posts are replied to or posted and you'll see that there is no lack of action happening.I realize you're interested in the numbers -- with a Marketplace post, that data is available.