I have about 5 sites, 3 of them are old and 2 are new. They are all MNS. I found a footprint for blog platform that has do follow comment links and that have all 0-2 comments on them, some are even PR3 and all AA. I know, wet dream. Anyways, I have built 10-20 comment backlinks for all of them for the past ~13 days or so and at first they were at their old spots, then they started rising in SERP-s and now they have either stopped rising or are not ranking at all. They sometimes come back to the same spot and then next day-half day disappear again. The amount of backlinks per day wasn't that much, why are the SERP-s doing like that. They are all keywords with really little competition, some are even EMD. Now for the past 5 days they have stopped their rise and disappear, appear on the same spots. Should I stop link building or should I continue? The anchor text is varied, some keyword, some totally irrelevant words. I have tried SEO for half a year now and only one site has come on the first page of google. I feel I have tried everything, I have not done spammy backlinks and stuff. Pretty frustrating to not see almost any success at all after all the work. The pages are not over optimized also, they have the keywords in url, title, description, tags, H1, one time bolded in text and that's all. Help and suggestions are appreciated.