From my experience no matter how many backlinks you build to your site as long as you didn't optimize your site with ON PAGE FACTORS, they won't work.
so if you want your backlincks work then "on page factors" are the first step.
when you're done with that then build your bakclinks by following the rules below"
-Make sure your links are from different ip address
-Your link building speed should look natural
-Your links sources should be from different sites
-Your links should not come from links pages. avoid pages with more than 50 outbound links
-Don't build your links on home pages only. try to link to different pages
-Your links frequency should vary
-Use diffrent keywords as anchor