Link building for search engine optimization with text links could be a viable proposition but you have to be very careful about selection of the appropriate provider so that you get the best results for your optimization process.

Though it is true that whatever link you add to your site could add to your optimization process to some extent, inbound links from reputed and well published pages could of immense value for the purpose. For example if there are inbound links from the popular websites like say MSN, Excite, Rediff and such others to your site or from web directories like the Yahoo, and DMOZ then it will be immensely beneficial for your site and enhancing its page ranking on search engines.

You should also remember when you buy links that apart from getting page rank on the result pages of search engine, the relevancy and effectiveness of your link can also give you good ranking on the web directories, another major avenue of getting more traffic and generating more revenue on the web.

It is a general trend with the search engines and web directories to pay more value to certain links like the educational and government links more than others. Therefore if you can get more inbound links from these sites it would be highly beneficial for you. If you opt for links like the edu links this is what you achieve without much ado.