But SEO is a tricky business. You must walk a fine line between helping the search engine recognize your relevance on certain topics and deceiving it with artificially exaggerated signals. JCPenney, whether intentionally or not, took the latter route.

A New York Times recently called attention to the fact that JCPenney had been at the top of Google's search rankings for a wide variety of products throughout this past holiday season. Those high rankings weren't the just reward for stellar popularity or one-of-a-kind marketing prowess, however; they were the result of black hat , presumably used by SearchDex, the SEO firm JCPenney has since fired.

To be precise, thousands of links were placed on hundreds of sites across the Web--many of them completely unrelated to the keywords in question, some apparently abandoned, but all leading to JCPenney.com.

That's a huge no-no in the Google world, and JCPenney's results have now reportedly been deflated again. (In other cases, it should be noted, Google has not been so kind. On catching BMW performing similar tricks a few years ago, Google actually removed the company from its search results for a while, as The Times points out.)

The story raises all sorts of questions not only about black hat techniques like these--which, however morally reprehensible, are generally not actually illegal--but also about , given that the company that succeeded in getting away with the tricks for so long happened to be a major advertiser.