Pagerank and Spamming

Question

Let's suppose we have a graph with 4 pages/nodes which are connected. We also have computed the pagerank for this graph and now we want to upload a new page/node an increase its pagerank. I wonder if we also upload N more pages/nodes to act as hubs to the page we want to increase the pagerank, will we achieve our goal? (the first graph and the spam graph are not connected)

Answer 1

There are several ways to exploit Google pagerank as published in Google's 1998 patent application. As you have noted, each page you add to your site, adds to the total pagerank available on your site.

There is even a way to create a page with infinite pagerank: Create a chain of pages where each page links to the next. Have every page in the chain link back to the first page. The longer you make this chain, the more the pagerank of the first page will be.

These algorithmic weaknesses are very hard to exploit in the real world.

First, Google has modified the algorithm from what it originally published in its patent application. Some of their updates have been to close weaknesses such as this. They have not published their current algorithm or a list of changes they have made.

Second, Google will only crawl pages that have above a certain pagerank threshold. That means that googlebot will not even crawl lots of extra pages created for the sole purpose of manufacturing pagerank. If googlebot doesn't crawl them, they won't be used in the pagerank calculation.

Third, Google actively penalizes sites that it detects trying to spam its algorithms. This may include preventing the pages on a site from passing any pagerank whatsoever. Google is now very good at detecting generated pages with no content, or with generated gibberish. Creating useful pages with real content to put into such a scheme is more effort than it would be worth.