Tagging is must and the main identification of your information linked to the user out there. If you tag well and keep updating the tag list according to the search surveys, you can easily make up to the PR of yahoo but there are already many experts who can even pay up to the mark where it can earn the right to be on top or near the headlines where people catch to read
Yes, it works but the words and data must be exactly selected and typed as the way the user is going to search while he is about to write in his search box.
PR gaining is a heavy work task for both the editors and the data collectors of the site. They have to be in a balanced mode to make the inflow of users via correct alphabets tagging on all the blog or on the index they are offering. It also takes smart audience to know what type of words they come up with when they are about to search on the internet.