“Build a better mouse trap link farm and the world will beat a path to your door.” -QuadsZilla

Gyongyi and Garcia-Molina’s Stanford paper on Link Spam Alliances illustrates the vulnerability of Single-Target Spam Farms to detection.

Most importantly, we find that there is an entire class of farm structures that yield the largest achievable target PageRank score. All such optimal farm structures share the following properties:
• All boosting pages point to and only to the target,
• All hijacked links point to the target,
• There are some links from the target to one or more boosting pages.

That’s nice for the classroom, but any 2005 Search Engine Spammer worth his salt knows these assumptions fail in the real world. Page rank is dead. SERPS are what matter. Using a pre 1999 Page Rank formula or the formula published in ACM Transactions on Internet Technology (TOIT), 2005 will only yield laboratory results.

Both formulas dictate that massive link farms with sitewide-links to a single target is optimal. In the real world, we call that Googlebowling.

Here’s what you can take away from the paper:

Solution 1 often fails to identify non-regular farm structures (like the one shown in Figure 13), which are typical of more sophisticated (and higher-ranking) spammers.

Single-Target Spam Farms are as sophomoric as 30-Keyword-Meta-Tags and sitewide-links. Yes, they once worked great. No they don’t work any more. So don’t use them.

Solution 2 works to identify spam farms if the amplification factor of a group is close to 1/(1 – c), In English, that means you need to link to external subject authorities from throughout your spam farms. So, instead of figure 13 above, your linking structure will look more like this:

As they point out:

detection is in its infancy, and as one develops better tools for combating spam, spammers adapt and devise more resistant schemes.

Always be adapting.