I have been searching around to increase my website backlinks in search engines, then I bought several PR1 - PR5 Directories around 10 directories in total and added a Text Link to my website. The outcome after 2 months is outstanding my backlinks grow from 2,895 to 7,845 and it increase daily around 200-300 links. You can see the outcome from the below link.
Google and Bing are very slow to add backlinks, however Yahoo , AllTheWeb and AltaVista are very generous in backlinks. My target is to take my website from PR3 to PR5 or PR6 within the coming 6 months. Finally my advice is buying one way links in High PR directory with high link popularity such as Defstu.com one of my directory (+30k Backlinks) or submitting your website to a good managed Free Directory will pay back well for your website backlinks.
my Own Free And Paid Directories are listed below: