I was wondering how effective 3waylinks.net or linkracer.com are ? Any feedback or recommendations for any other similar services ?
I wouldn't bother. At best they'll work for a while & then get banned ... meaning your site loses rankings in a year or so. Worst case, you link out to a bad site & get banned altogether.
One thing I can say for sure. DoA is very right. I'm a linkracer customer and I regret it very deeply. Articles got deindexed from google. Their propagation service isn't working anymore, which means the articles aren't getting distributed over the network. The "founder" of LinkRacer, Brian Prins, has been exposed as a fraud in the past! And it would not surprise me if he's doing the "old tricks" again with LinkRacer... There are many many many unhappy customers (all complaining publicly on another popular internet marketing forum). I've not used 3waylinks.net, so I can't say anything about it. Hope this helps. If you need some additional info regarding LinkRacer, I'll be glad to provide it.