A few stats:
£578.90 paidonresults over 12 months. which is $438.19 over 6 months.
plugrush $430.59 over 6 months
juicyads 664.802 over 6 months
A grand total of $1533.58 over 6 months
or estimated $3067 over 12 months.
Take off domain renewals of $100 and CDN $100 (We use CDN77 at present)
Hosting at $600 a year? ATM they are all on a 4TB shared hosting. Using about 1TB including backups. A lot of those images can be cleared out
So a great profit and return in year 1.
Also to note is that only 10% of traffic is UK yet all of the paid on results money is UK only. So if you targeted it to the correct regions (largely USA) then you could get a much better return, I haven't had a chance to do that though.