It really depends on the traffic and what site you are running.
I know a lot of webmasters with free/dump/trade sites that have a lot of traffic (200,000ish uniques daily) that make shit trying to convert their banners into sales.
Some of them i got to use the "no worries" program which pays per raw click and they are making anything from 20-200usd per day just from ppc. Not costing them 1 adspot extra.
I dont think its that easy to just say ppc isnt paying, it depends on a lot of factors.
- Sites traffic.
- Sites model.
- How many clicks you can generate.
You can send 20k se-typeins through a fakeplayer banner and make nothing, or do the same and make a nice amount. Same with ppc. But with ppc you dont have to worry about sales.
I would recommend everyone that has conversions going to the bottom of the ocean to give it a try. If they dont like it, they can always get back to trying to catch some sales
/myhumbleopinion.