The most popular search engine GOOGLE was originally a search engine project that used links from one website to another as a vote for ranking a page. (Yet another win for democracy).

But unlike the usual democracy this one does not consider all votes to be of equal value. Being linked to from relevant and popular websites counts much more than being linked to by small unknown low ranked websites, what you should do and is common these days is to find relevant websites that will trade links with you.

Do not post your website to Free For All links websites, it is a waste of time, those pages have no content and are not ranked altogether by search engines, if they are they are usually ranked for irrelevant keywords.