Real-life applications for PageRank

Many website owners focus on getting good PageRank for their websites. PageRank, or PR for short, is Larry Page's famous algorithm for determining the relative importance of pages. Google's ranking algorithm uses PageRank as one of its inputs (but certainly not the only input — you can rank highly in Google even with a low or non-existent PR) and so it's the topic of much discussion and debate among webmasters interested in getting their pages to rank highly in Google's search results.

The other day, though, it occurred to me that there were other, real-life applications for PageRank. But first, let's briefly revisit what PR means.

In the Google world, each page is assigned a measure of its importance based on how many other pages link to it. In general, the more inbound links to your page, the higher your PR. The page then votes on the importance of still other pages through its own links — in effect sharing its PR value among all the pages by dividing that value equally among all the links. The fewer outbound links a page has, the more its “vote” is worth to each of those pages. There are some complex mathematics that keep track of everything.

As a general rule, then, what you want to do is get as many inbound links to your pages but to minimize the number of outbound links, preferably keeping them within the pages of your own site(s) so as to spread your PR “manure” amongst your own pages and not that of external sites. Of course, if you're too stingy then you'll have trouble getting anyone to link to you, so you can't avoid those external links completely if you want to be a good Web citizen. But if you have a high-PR page then links from that page are valuable, and you want to be picky about who you link to.

So how does this apply to the real world? Well, my daughter's just signed up for the Multiple Sclerosis Read-a-thon, which means we have to hit up our friends and family to sponsor her reading. Not our favorite task, really, but it's for a good cause and it encourages her to read, so we do it.

Here's where PageRank comes into play. Say the PR represents the willingness of a family or individual (which I'll just refer to as “family”) to donate to charitable causes. A “link” from A to B means that family A donates money to family B's cause. Ignore for a moment how wealthy (or not) a family is. The more times a family is “linked to” (asked to donate), the higher the family's PR. In other words, if you keep pestering your friends and family to donate money to your kid's cause, you'll be more susceptible to being asked for donations yourself from those same friends and family, because of course they contributed to you, so why wouldn't you contribute to them?

Just like with real PageRank, a family's PR gets shared out proportionately based on how many times it donates to other families' causes. As you can imagine, then, having a high PR makes you more valuable. The trick for donation-getting success, then, is to find those families with more incoming contributions than outgoing contributions. This gives them a high PR, which they can then share with you by donating to your cause. The fewer outgoing donations they have, the more money they'll be willing to contribute to your cause.

Who said PR only applied to Web pages?

Eric Giguere is the AdSense expert who wrote Make Easy Money with Google and the new e-book Uncommon AdSense.

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