Last year, I paid a dofollow blog commenting service $230 for 1,000 comments on 500 blogs.
Also last year, I paid a nice Malaysian fellow $5/hr to comment on blogs for a number of my sites. He put in about 300 hours writing unique and relevant blog comments.
Very recently, I paid another fellow $125 for comments on 3PR6, 7PR5, 10PR4, 12PR3, 15PR2, and 15PR1 dofollow blogs.
I did not see any effect from the two tests I ran last year. I have yet to see any effect from the test I ran recently. The site I promoted actually received zero visitors for the last two days.
I hate to cause people trouble, and I know the blog comment sellers are doing a great job at blog commenting, but I have to tell all NetBuilders:
It appears that Google is ignoring all links from blog comments -- even DOFOLLOW blogs!