When you see a comment on a blog post that says “Great post, I have bookmarked and will return. You are truly knowledgeable,” or “It is amazing how you became such a leader in your field, I can’t imagine why you don’t have more traffic” or some other topicless, pointless, silly, awkwardly translated, or uselessly complementary post, it is likely spam. Any application that accepts hyperlinks can be targeted by automatic posts.
Why do it? Simple. By posting on your blog or my blog or some other online forum, the spammer is adding links that point to their web site, thus (in their mind) artificially increasing the site’s search engine ranking. As I’ve mentioned before, an important aspect of search engine optimization (SEO) is backlinking. It’s one way that the search spiders are able to detect the importance of a particular web site – how much traffic is leading to it from other sources. Fun fact- it doesn’t work! This shady, obnoxious, and clearly black-hat technique provides no actual benefit now. Google has made efforts to minimize the effectiveness of these techniques through their various updates, most notably the recent Penguin update. The saddest part is that at times the SEO companies who do it may not be informing clients about their shady tactics. Many blogging packages now have methods of preventing or reducing the effect of blog spam, although spammers have developed tools, and will always continue to, in order to circumvent them. Even still, those comments and those links, provide no measurable value.
So what can you do to alleviate spamdexing? (I really do love that word). There are a few options, none are 100% effective, but mixing a few of them up can help you alleviate some of the worst offenders.
- You can use the ‘rel=”nofollow”‘ attribute on reader-submitted links; most blogging platforms do this by default, although there are ways of changing the code and ways of getting around it anyway.
- You can block specific keywords or repeat offenders (say, different pharmaceuticals or brand names).
- You can add a CAPTCHA or a way of ensuring that any commenter is a human. However, these can be hard to read; I always mess them up – I feel like I’m trying to see the dolphin in a Magic Eye print from the 90’s or read someone’s ultrasound. They also can be annoying to users; anytime you create an additional field, you miss out on potential interactions with your customers. By adding screen CAPTCHAs, you run the risk of reducing the amount of interaction on your site.
- You can disallow links in posts or automatically mark an item as spam if it has more than two links listed.
There are a few other methods, but these are the most common. If you can combine two or more of them, you have a much better chance of limiting, if not eliminating, spamdexing on your site. Otherwise, you just have to be vigilant and report spammy comments.