Call it what you want – blog spam, comment spam, spamdexing (which happens to be a personal favorite) – it’s always annoying. It is the term for “automatically posting random comments or promoting commercial services to blogs, wikis, guestbooks, or other publicly accessible online discussion boards.” (Thank you Wikipedia for that very clear definition – the best one I was able to find on the subject.) FYI – in no way am I indicting actual spam in a can; it just made for a decent picture for the post. I used to love that stuff with scrambled eggs as a kid.
Back to the story… 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 aren’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 the 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 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. This is shady, obnoxious, and clearly black-hat to automatically place nonsense or useless comments. Google, in particular, 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.
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 is the distributed approach, which is used on this site and other WordPress blogs by Akismet, but even this isn’t totally effective.
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.