Anilrgowda

Re-routing
A similar tactic to JavaScript links is to re-route your link to prevent spidering and transfer of PageRank. What is especially bad about this practice is the link often is coded so it appears to be a standard link. Watch for re-routes, and avoid link partners who use them.

Some dishonest webmasters don't mind the transfer of PageRank. Their main concern is sending traffic away from their site via outbound links. This is even more true if the link goes to a competitor's site, or perhaps to a complementary business, that may also contain competitor's links.

Hidden Links
To avoid having a visitor click of an outgoing link, the link doesn't appear visually on the page. It's hidden or cloaked. The search engines can read it, but no visitor traffic will find it. As with all hidden text, highlight the entire page with Ctrl-A. If your link is cloaked by hidden text, it will show up with that keyboard command.

Robots.txt
Occasionally, you will find that unscrupulous linking partners will code the robots.txt for the page to No Follow. With that command, the search engine spiders will not crawl the page. If that non-indexed page is where your link resides, it will never appear in the search engines. The page will never be spidered. You will not only not get PageRank transfer, you will not get any incoming link popularity benefit either.

A variation of the robots.txt theme is to place your link on a frames web page that doesn't have coding requesting the search engine spiders to crawl and index the page. Once again, your link provides less than the agreed upon value. You should, in both cases, receive some visitor traffic from the link, however.

Orphaned Pages
Another trick to watch for is the non-linked orphan link page. Often, an underhanded link partner will dutifully place your link on the alleged links page, as agreed. There is only one problem. The link page can't be reached from anywhere inside the website. The supposed link page is not part of the site map. The page is also usually a challenge, of epic proportions, to locate in any of the directories or sub-directories. Because the page is an island on the Internet, it will have next to no value as an incoming link, either for traffic or for link popularity.

Other Tactics
There are a few basic tricks that most people can readily spot with minimal difficulty. One of the most common is simply never receiving the return link as promised. The linking partner never puts it up at all. The hope on their part is that you won't ever check. They usually know from experience that many link partners don't look for their link.

Often, the one-sided link partner will indeed place your link on their page. Of course, your link disappears from the page after about a month. Your link get deleted. As with the case of never being linked, the disappearing link artists depend on you never checking your link partner pages. When your site has thousands of incoming links, you are especially vulnerable to having your links vanish, or never appearing in the first place.