Hi. Ranking of main 18000 keyword of my site stuck on third page for a long time. It was on 22-24 postion when website had 18 pbns, and now it on 20-21 position and site has 30 pbn links. Last link i added week ago. 10 pbns has different exact match anchors, 20 others - partial, lsi, couple brand. Also i have ~70 web2.0s, profiles, comments links with brand, naked, generic keywords. Other keywords also stuck on 3-4 page. Competition is high but why i see almost no movements after adding last bunch of pbns? I expected more than move from 24 to 21 with 12 pbns. Onpage is ok. Perhabs i should add more pbn with brand anchors?