how link partners cheat

Overview:
Google created Google Page Rank (GPR), which places more emphasis on quantity as opposed to quality. In other words, higher ranked sites are more important for the Internet than quality sites. As a consequence, webmasters become more interested in creating a high GPR sites than producing a quality info for the Internet.

In short, a good link trade means that you should trade links with pages of the same or similar page rank.
For example:
If your outward link is on a PR4 page and your link partner's inward link is on a PR4 page, you have a good trade.
If your outward link is on a PR4 page and your link partner's inward link is on a PR1 page (or no link back at all), you have a bad trade, and your site's PR will go down.

Note: To find cheats, you first need to have a Google Toolbar installed.

How link partners cheat:
Unfortunately, because GPR is so important, many (and I mean many) webmaters cheat. The following list shows some common cheating practices and methods for you to check.

1. Many webmasters use auto link/click scripts. They or you can add your link instantly to them and the more clicks you send them, the higher you go up the list and the more clicks you get back. Many of these scripts are okay for click trading but are useless for PR purposes. Even though your link may appear to be on a PR6 page, and you get clicks from that page, you are most likely not getting any PR credit from it.
How to check: First, right click on your link and click properties to see if your URL is in a script. If it is, search Google, Yahoo, and MSN to see if the site is backlinking to you:
Google: link:yoursite.com or link: yoursite.com (notice the space between 'link:' and 'yoursite.com')
or yoursite.com -site:www.yoursite.com -site:yoursite.com (this option omits your own internal links - therefore, more accurate).
Yahoo: linkdomain:www.yoursite.com (for searching links going to all pages of your site)
or linkdomain:www.yoursite.com -site:www.yoursite.com (for searching your front page only)
MSN: linkdomain:yoursite.com (for searching links going to all pages of your site)
or link:yoursite.com -site:yoursite.com (for searching your front page only)

You can also use the reciprocal link checker and search engine simulator on the previous page.

2. Using redirects is a common cheating practice. Even though your link may be showing on a PR6 page, you won't get PR credit from that page if the cheater redirects your link through a low ranking page first.
How to check: Right click on your link and click properties to see if there is a redirect attached to your URL. Also, check your stats to see if the incoming click is coming from the correct page.

3. Some webmasters add a nofollow tag to your link. Even though your link may be showing on a PR6 page, you are getting no PR credit from that page if this tag is attached to your link. This tag makes your link invisible to all the main search engines.
How to check: Click view in your tool bar and then click source. Search the page, using find in edit, to find your link URL and see if there is a nofollow tag attached.

4. Using an iframe inappropriately is another method of cheating. Even though your link may appear to be on a PR6 page, it is not. It is in an iframe (window) of a lower ranking page. Hence, you are only getting PR credit from the lower ranking page.
How to check: Click view in your tool bar and then click source. Search the page, using find in edit, to see if your link is there.

5. Some webmasters omit the www from your link. For example, instead of linking to http://www.yoursite.com (as they should) they link to http://yoursite.com. This means that http://yoursite.com (a different domain) is getting the PR credit instead of your main page http://www.yoursite.com which should be getting the PR credit.
How to check: Right click on your link and click properties to see if the www has been included in your URL.

6. Some link partners link to your site from their non www page. For example, they link from http://linkpartner.com instead of http://www.linkpartner.com. Google does not give PR credit from non www pages.
How to check: Check your stats to see if your link is coming from a non www page. Also, click on the link within your stats and view your Windows address field (on your tool bar) to see if your link is coming from a non www page.

7. Some webmasters use robots.txt to stop search engines spidering a particular page.
How to check: Go to the page where your link is displays and then add /robots.txt to the end of the URL in your Windows address field (on your toolbar); for example, http://www.linkpartner.com/robots.txt -Go to that page and if there is anything on it that says disallow then it is probably hiding your link from Google and other search engines.

8. Many webmasters can detect the IP addresses of search-engine robots and there are plenty of updated lists out there. The webmaster looks at the IP address of the spider and when confirmed, it delivers a page designed just for the search engine - without your link.
How to check: Pick any link near your one and see if it has a backlink from Google; if there is no backlink, and Google's does not have a cache of the page containing the links, then its best to stay away from that site.

How to stop webmasters cheating:
If webmasters are cheating you out of GPR, the most obvious thing to do is to stop linking to them. However, sometimes these sites (especially the ones using link/click scripts) can be good for click swapping purposes, even though they are cheating you out of PR. In this case, you can keep trading clicks with them without giving them PR credit from your site by adding the nofollow tag to their links. In other words, if they cheat you, you can cheat them right back. To get more info and find out how to do this click here