We have got some GREAT results using DO follow blog comments and top commentators on various niches.

Here are the details for both the above mentioned services :

1) Do follow blog comments :
Some of the blogs don’t have no follow attribute in the comments section of their blogs. Thus comments in those blogs can have a good link to your site.
For example : http://www.seotops.com/ : this is a PR 4 blog and the comments are do follow. Thus you can see we can easily generate lots of links through posting comments on posts like http://www.seotops.com/japanese-submissions_398/.
The links obtained though this method will be high quality, related, incontent links which google loves.

2) Top Commentators :
Some blogs give site wide links to the top commentators, thus this can be another source of do follow links from authority sites (which otherwise wont be possible in any other way other than paying them).
For Example : www.shoemoney.com is a PR 6 site having high authority and 10k + daily uniques. We can be in the top commentators by posting around 3 comments for each post he makes on regular basis.
We have made a list of such sites in every niche and are using this method widely for promotions of various clients and are getting good results in google  by doing the same.

Initially we did it as a test on our own websites and then repeated the process for some of our premium clients, and we got Excellent results.

We might not launch this service for every one for another week or two (training the team to handle bulk orders).
We will be getting back with more updates from the core SEO team as well as this blog will get regularly updated with latest happenings, tips and tricks of the SEO world.