I have tested this "method" on 5 of my websites. Very poor results, almost no real improvement in serps, even for "easy" long tail keywords.
This is, essentially, a downgraded version of other link building services found on WF.
At the moment I only use a select few websites for fast site indexing.
You'll find that people who claim that this "technique" works don't have any real proof or think that ranking for completely obscure-super long tail-phrases that no one is interested in is an achievement.
Basically, the technique is 95% useless and definitely not worth the effort.