How many link partners are there?
Exchanging links with other sites is a promising way to increase your Google PageRank and to draw visitors to your site. Good incoming links have a positive effect on your search engine rankings and they also bring targeted visitors to your web site. A recent article in the eCommerce Times summarized it:
Eventually, you will be king of the link hill in your area of interest. And you will be very hard to knock down, unless someone else is as determined as you are. More than likely, they won't be."
But how many potential link partners are there, and what is a realistic goal for your linking campaigns? How many link partners should you have?
According to http://www.webhosting.info/domains/country_stats/ there are more than 20 million US domains, 2 million domains from Germany, 2 million domains from United Kingdom, about 1.5 million domains from Canada and about 1 million domains from France. So according to this site, there are more than 30 million domains in total.
It seems that there is no accurate total number of domains so let's say there are about 30-40 million domains.
To calculate the number of potential link partners, we have to lower the number of 30-40 mill. domains considerably because most companies own several domains at once. For example, Microsoft owns microsoft.com, msn.com, hotmail.com, msnbc.com, microsoft.de, microsoft.fr, msn.ca, msn.co.uk, and many, many more.
Then we have to decrease the number once again because big companies such as Vodafone, Toyota, Microsoft or Bank One will probably not answer to link request mails.
In addition, we have to cut down the number of potential link partners by the number of domains from countries whose language we don't understand. They probably wouldn't understand our link request message, either.
The technical aspects
We have to take into account that every search engine indexes only a small part of the whole World Wide Web. Some domains have fallen out of the search engine indexes, some domains have changed their owners and a lot domains are redirections and not connected to the Internet at all.
Besides, it's difficult to find many different link partners because search engines only return 1000 results at maximum per search request, even if they display "results 1-10 of about 7,380,000". Just try to get beyond the 100th result page and you'll see that it's not possible.
For instance, let's search for "humor" at Google. Google tells us that there are more than 24,600,000 results, yet we cannot get past the 999th result.
What does it mean to you?
If we take all those factors into account, there are probably only less than 1 million domains remaining who could be potential link partners for you.
On the positive side, most link partners can publish your link on several of their domains. In addition, they can link back from one of their domains to several of your domains.
At the end of the day, remember that it's not the quantity of links that counts but the quality.
It's also important that the web sites that are linking to you have a similar topic as your site. If you sell flowers on your web page, then links from other flower pages count more than a link from a web site that links to all kind of sites.
This means that even a few dozen links from popular sites that have a similar topic as your site can be sufficient to get a better ranking as a site with 15,000 web sites linking to it.