Link popularity and click popularity are determined by each search engine. AltaVista may calculate a high popularity for your site, whereas Infoseek may calculate a low popularity for your site. Each search engine may also use the popularity information in different ways. It will all depend on their specific algorithms.

Popularity is becoming more widely used by search engines. Therefore, it is a very important consideration when trying to increase your ranks. Hypothetically, if you have two sites that have equal content and equal meta tags, then the site with more popularity will rank higher.

Link Popularity:

The link popularity of your site is determined by:
The number of web sites that are linking to your site (the web page that your link appears on, must be indexed by the search engine - just using those "free-for-all-links-pages" is not the kind of link that you're looking for.), The popularity of the sites are that are linking to your site and the similarity of the content on sites that link to your site. Link popularity is used by every search engine to some extent. Ways to increase link popularity will be discussed below.

Click popularity:

Click popularity is the number of clicks that your site gets when it comes up on a search. So if your site is number 3      for a search, and it is being clicked on by people more than number 2, you can potentially move ahead of      number 2.(If the engine uses click popularity in their algorithms.)
Excite and Direct Hit use click popularity. Also, engines that are associated with Direct Hit, like Hotbot, indirectly      use click popularity.
You can increase click popularity by having a good title and a good description of your website in your meta tags.

How to find out who's Linking to you:

Different search engine process differently

Excite Type into search box: www.yourdomain.com This will give you a general estimate of your popularity. It will also tell you approximately how many pages from your site are listed with excite.

Infoseek Type into search box: link:yourdomain.com This will give you all of the pages which link to you, including your own. Link popularity is very important in getting good ranks in Infoseek. I just read some new info that said that if you link OUT to highly popular sites, this may increase your popularity. However, this may only work in Infoseek. Also, it needs to be a site which relates to your content.

AltaVista Type into search box: link:yourdomain.com This will give you all of the pages which link to you, the same as Infoseek.

Hotbot Type into search box: linkdomain:yourdomain.com Again, this may give you some of the pages which are linking to you from your own domain.

Webcrawler Type into search box: http://www.yourdomain.com Webcrawler may ask you what you want to do with this URL. Click on "Search for web pages containing the URL in the text." It will give you a general estimate of how many pages are linking to you and also tell you how many of your pages are listed in this engine.

How to increase link popularity:

Reciprocal Links
There are varying opinions on whether or not to get reciprocal links and if you do, where you should put them. Here is our opinion - The internet is a web and it is joined by links. If you are offering good resources, people will bookmark your site and come back. If you aren't, they won't. Part of offering resources is suggesting other places to find information. We're not suggesting that you put links off your site on your home page, we're not suggesting that all you do is to provide a directory of other links.

We started with a one page resource directory. From there, we built it up to over 10 pages of links that go to sites that have content similar to our own. We started by simply linking to anything related to us. Now we are more fussy. We will only link to a site that will place a reciprocal link to us and we only link to sites that have quality content. (Yeah, it's a lot of work to maintain that small directory).

Online Directories
Getting listings in directories will not only boost your traffic, it will also increase your link popularity. It is especially relevant to link popularity because these directories are mega popular (remember the more popular a site is that links to you, the more popular your site will be rated).