Adventures of a pseudo advertiser

So recently--within the last couple of days--I was checking my email and I noticed that I had received an email from payperpost.com telling me that they had added 100 dollars to my account to try out their service. I had been an advertiser for awhile, but never actually posted an Opportunity. I decided to check it out. I created an Opportunity for approx. $23 (I know, I'm generous, but it wasn't my money so what the heck!) I promptly had someone post an article about my website topicks.info I then posted another Opportunity for $5 and allowed 5 people to post an advertisement. (5 dollars per person) This result was much less satisfying. One person even wrote that my web application was "ad-ware" and that it was "advertisement" based. Neither of which are true and I don't know how he/she would even come to that conclusion unless they never even visited the site in the first place, which is highly possible/probable. So my advice to you, if you are advertising, would be to pick blogs with higher ranking, (even though you pay a little bit more money per post) because the people who write for the minimum 5 dollars do a pretty crappy job in general.

What are your experiences with PayPerPost and the like?
Are there any other pay-to-blog/get-paid-to-blog sites out there that you recommend?