Battle of the comment add-ons: 6 services compared

Commenting can play a major part in making an author's blog post deeper, and more interesting to read. It's like having a discussion in real life versus simply hearing someone speak--there are details, and alternate angles that can come of making ideas go two ways instead of one.

When creating a personal blog or one for business, there are the standard comment systems that come with your blogging platform, as well as a whole new breed of third-party tools that can add extra functionality, and potentially a deeper level of discussion to your site. So which ones are worth installing?

We've picked six of the major players in this space, and talked about what makes them more useful than the ones that come built-in to popular hosted blogging services like WordPress and Movable Type. Even if you're not on one of these two platforms, several of these solutions will work on a site you've built from scratch.

CoComment lets your readers subscribe to comments on a blog post, and share that thread with other CoComment users. It scrapes people's comments from threads they've replied to, so they can monitor and access the responses for multiple sites in one centralized location.

Adding CoComment to your site doesn't involve replacing your current commenting system, but it means you're signing up to be part of the CoComment network. If your users are active members of this community you might get new people discovering your content and taking part in the conversation--which could translate to site growth and prominence. The two things that turned us off to the service were the sometimes slow service and distracting ads that take are found on CoComment's main service.

Co.mments is a plug-in for blog owners, as well as a simple browser bookmarklet that lets you (or your readers) track conversations regardless of whether or not the stock commenting system offers such a feature. It works similar to some of the Web commerce price trackers we've looked at before, and will notify you if there are changes. Commenters can keep an eye on all the conversations they're tracking in one spot, and quickly browse through them like an river of news with a full list of keyboard shortcuts.

If you like Wordpress' built-in comment system and Askimet spam-catching plug-in, and don't want to ditch it for some completely different system, then Co.mments is a simple way to add tracking services for your readers so that they will know when to come back. However, it doesn't offer some of the advanced functionality of the others, and is mainly for helping your users keep track of what's going on with various threads on your blog--not making them more advanced. Several other services we're profiling offer subscription features of their own, but we liked Co.mments' in-box that lets you go catch up on multiple conversations in one place.

Continue reading to find out the other four services and which ones we picked out of the bunch.

Disqus is a distributed commenting system, meaning if several sites have it installed, users can share the same identity (including login) on each site. Each user profile includes commenting karma and a public page that's similar to Twitter with comments showing up in a reverse chronological river.

As a blog owner this means you're buying into being in a Web ring of sorts--similar to CoComment. There's potential for users from other sites to discover your content because of user cross-pollination.

Replacing the stock commenting system with Disqus doesn't mean all your old comments will go kaput. There's a built-in tool that will slurp up all the previous comments and place them into upgraded Disqus conversations. The tool does take some of the spam and trolling filters out of your hands which advanced users might not like. The upside to that is that the "clout" system of user karma and voting helps self-police problems if you've got an active community of semi-responsible individuals. It also offers up the option for your readers to read and post comments via e-mail and mobile phones--something few others have.

Intense Debate is very nearly identical to Disqus but there are slight differences in style and presentation. Like Disqus it will import comments from your old blog in case you're in fear of losing the existing discussion from your old posts.

As a site owner, Intense Debate is worth installing if you've got several blogs on several different platforms, as there's a simple moderating interface that combines all of the comments into one feed. It's also got analytics that let you view which blog is getting the most comments and from what users, which can help your figure out which posts and which sites are getting the most audience involvement--something that can be crucial in figuring out how to cater to what your readers want.

For spam and trolling protection, there's no system in place besides user moderation, which means if you have some yahoo posting on your site, it's up to you or other users to deal with him or her. The service promises to have a solution if the system becomes able to be gamed.

JS-Kit Comments is just one small part of a group of JavaScript based widgets and site add-ons that give you functionality your blog might not have had. The service offers up some of the basics like deep threading, and a WYSIWYG text editor. There are also some advanced tools like the option to leave video comments by linking up to YouTube or skinning it to match your site using CSS.

As a blog owner, compared to some of the others, JS-Kit is very customizable if you know your way around JavaScript. It also integrates Akismet, the antispam engine that you'll find as standard in both Wordpress and as a plugin for Movable Type. Using both systems, the tool will learn what's spam and what's not after some gentle help in the beginning.

The one thing it can't do is pull comments that were there before you installed it, making it a somewhat underpowered compared to Disqus and Intense Debate. The good news is that you can choose to simply put it in new posts going forward, while letting older posts keep the original commenting system.

SezWho is unique in that it's not a replacement for your existing commenting system, it simply enhances the one you have by offering membership into Sezwho's network. This network layers on a reputation and rating system to comments and users of your blog. Those users can vote on the usefulness of other people's comments, and that rating goes into an aggregate ranking that's a part of a user's profile.

Rankings are universal on any site that's integrated SezWho. User moderation from other sites sort out the good and the bad commenters so you can get the heads up on a user that's been perceived as problematic by others in the network. The system also has a promising analytics service that lets you keep an eye on some of your most active commenters and track how much they're using your site at the same time.

If you're thinking about enhancing your existing commenting system, SezWho is a viable solution that's nondestructive and could potentially lead to an increase in traffic to your blog with clicks from other in-network SezWho users who are tracking sites other users are visiting. Its analytics system is also more than you're able to get from the stock commenting tools, which as mentioned above can help you figure out which stories are getting the most community interaction.

Which one is the best?

Each service has tradeoffs. Many of the ones that entirely replace your existing commenting system put your blog at risk of suffering comment blackouts in the event the comment engine goes down. As we've seen with Amazon's S3 storage going kaput, relying on a third-party service for an integral part of your site can be risky, so if commenting uptime is paramount as part of a business or commerce site, you might want to have a backup plan.

Out of all the ones we looked at, we think Disqus and Intense Debate are about neck and neck in terms of functionality and usefulness for blog owners to take discussion to the next level. Disqus only slightly edges out Intense Debate with the mobile phone access, which honestly isn't a deal breaker or a must-have for most people. Both offer universal profiles, great threading, OpenID login, analytics and support for catching legacy comments from any pre-existing system. If you're on the fence, both services are free and simple to add to your blog--so it might be worth trying both on a test page and seeing which one your users prefer.

A close runner up is SezWho, which is used on several popular blogs and brings a style and flavor of its own that you might simply like more than the look and feel of the others. We like that it enhances the comment system you already have, and that your user karma might mean something more as the service expands into other fields like wikis and forums in the future.

Below we've put together a chart to illustrate some of the differences and similarities between the various services. It's far from detailing each and every feature offering, but attempts to cover as much of the overlap as possible.