A few months ago I submitted one of my sites to some paid directories and the traffic increased a while, but then dropped to the same level of traffic as before the submissions. If you only get a few weeks of increased traffic from high PR (and in some cases costly) submissions, where do you go at that point? After a while you run out of worthwhile directories that will actually do some good, right? So, where to go from there?
Why would you buy links if you can get it for free. There's lot of free directories where you can submit your site. Here's a good list.
there are many good free directories too. when you buy a link from a directory, how do you know if google will count that link?
There's lot of quality directories that has limitation on their links. Some fre directories would only allow 20 quality links in each category. That directories can be classify as quality directories.
google has started to ignore backlinks from paid directories. it's the reason that you loose your serp