Akismet is an anti-spam plugin developed by the makers of WordPress. It is designed to stop comment spam. The plugin is free if you are publishing a blog only for personal use. There is a $5 monthly subscription price if you are running a commercial blog. Whether you should fork over this fee for Akismet really depends on several factors. There are certainly reasons to pay this fee, and Akismet is known to be very good at blocking comment spam on WordPress blogs. In some cases, however, it is just not necessary.
Akismet comes pre-loaded when you install WordPress on your website. This is primarily what makes it so popular. It uses a system that is far from foolproof. Essentially, it creates a filter system that compares comments posted across multiple blogs. If someone is trying to post the same message on multiple blogs, for example, the Akismet database will catch that and block the spam. It will do nothing to stop manual spam, but automated spam is definitely a bigger issue because it will destroy your blog’s commenting area if you don’t find a way to protect yourself. Akismet is going to block a lot of that automatic spam that is generated by spam bots (software programs used for automatic comment spamming). But is it necessary to pay $5 for this service if you have a commercial site?
Well, there are a lot of other free options in the WordPress plugin database that will purport to do the same thing for free. One advantage of Akismet, however, is that is blocks spam without requiring the use of things like CAPTCHA forms. Many of the free alternatives require a CAPTCHA form or other device that is inconvenient for commenters. However, there are some plugins like Spam Free WordPress that do not require a CAPTCHA but require something like a password. This can also stop WordPress comment spam while being a bit less annoying to commenters.
You also want to consider registration spam. Blocking all the comments in the world is not going to stop the spammers from using spam bots to register at your website. Akismet is not an anti-registration spam plugin, so you would have to use another plugin if you are allowing registrations at your website. For example, you may wish to have members register and log in to leave comments.
If you want to maximize the ability to get comments on your WordPress blog, you may wish to not require registration to comment. In that case, Akismet may be worth the price of admission for commercial sites. However, you could still use something like Spam Free WordPress or another free plugin first and compare results.
When you are first starting out as a blogger, you are generally going to be receiving little to no traffic. This means you want to keep expenses low to maximize your chances of turning a net profit. You may wish to start with a free plugin first and then move to Akismet as you start to get traffic and visitors to your blog. That way, you are getting actual value for your Akismet subscription instead of spending $5 per month on something that is not yet making you money. Also consider that you are already paying a hosting fee for your blog and website.
One good thing about Akismet is that you can expect it to remain up to date with WordPress’s own updates. Other plugins come and go, but Akismet will consistently be there as long as the WordPress developers decide to maintain the service. This could prevent hassles in having to change to different anti-spam plugins later if the one you are using falls out of date. However, always consider the bottom dollar when making this decision. It is not really that easy to make a lot of money with a blog, so think about getting some consistent traffic first before spending money on every little thing like Akismet for your WordPress blog.