As many people have found out, you can buy domains with high pagerank (PR) such as PR4 or higher on auctions such as eBay.

Why would anyone pay a significant amount of money for just a domain that doesn't even come with a business, website or hosting?

Well, the primary reason is so that people can take this high PR domain and use it to host a website primarily for the purpose of linking to websites with lower PR or no PR. Since search engine spiders visit high PR sites more often than low PR sites, the idea is that the spiders will visit the high PR site and then follow the links to lower PR sites.

This strategy may enable the lower PR sites to become indexed faster by the search engines, and with enough links from higher PR sites, the PR of the linked sites could increase.

While this may sound like an excellent idea, there are a few things to watch for in purchasing high PR domains:

1. Unscrupulous sellers have been known to fake PR. Without going into how this can be done, you should use free online tools such as http://www.seologs.com/pr-check/pagerank.html and http://reladvance.com/metrix/find_metrics_results.php to independently verify the PR of the domain you are thinking of buying. Also, you should install the Google toolbar http://www.google.com/tools/toolbar/ on your computer so you can always see the PR of sites you visit.

2. The PR may not last past the next time Google computes PR. Sellers never guarantee the PR will last any length of time, and for good reason. How Google exactly computes PR is mystery and changes frequently. A PR5 domain could be a PR0 domain the next time Google runs their PR algorithms, and oops -- there goes your investment.

3. If you do find a legitimate domain with high PR that lasts, a backlink from that domain website to a lower PR website may not be all that effective. Search engines look at "relevancy" of the backlinks, and if the high PR domain is about "cameras," then it will be able to provide relevant links only to sites about cameras.

4. One backlink from a high PR site is like a drop in the ocean. It takes many backlinks to get and maintain a high PR and consistently high indexing over time. Buying a lot of high PR domains to get a good ranking and indexing could end up being a very expensive proposition.

So look before you leap when considering the purchase of a high PR domain. There are so many other less expensive ways to attain indexing and PR that you may want to consider before laying out money for a domain whose PR may in the end do you little good.