Blog commenting services have been consolidating over the past year, thinning out a once crowded market. Most recently, JS-Kit, maker of blog widgets for polls, ratings and comments, acquired competing commenting company SezWho — which itself absorbed blog semantic search firm Tejit last May. And just last fall, WordPress parent company Automattic bought comment provider IntenseDebate. No financial terms were disclosed for any of these deals.

JS-Kit says it will keep the SezWho service live for users for the next 30 days, at which point they will have to adopt JS-Kit’s own service or look elsewhere. SezWho was distinguished by its reputation system, which allowed users to login with their emails or OpenIDs to establish a reputation across any and all SezWho-synced sites. Other players in the space like Disqus (which VentureBeat uses, incidentally) trailed behind when it came to integrating their archives with other commenting services (so that users wouldn’t have to stick with just one forever).

The blog commenting field had been heading for consolidation for quite some time. Too many individual and mutually exclusive rivals were battling for the same audience. Increasingly, users are looking to build solid reputations and personas for themselves through their commenting. But when they frequent sites and blogs that use varying commenting systems, they have a hard time cementing a consistent front. The state of the economy has only weakened these companies further, causing large risk-averse sites to choose the same stable options over experimental startups.

Even though many of the smaller commenting services have dropped out of the race, JS-Kit will still face competition from IntenseDebate, which has a fair amount of traction, as well as Facebook’s new widget that uses Facebook Connect to echo all comments made elsewhere back to users’ profiles.

Last summer, JS-Kit bought commenting company Haloscan. It last raised funds in October, bringing in $3.6 million in a second-round of funding from Altos Ventures and TEF3. It counts JetBlue Airways, IAC and Sun Microsystems among its customers.

Sezwho had taken $1.3 million in capital from a group of investors including KPG Ventures, but all of its backers have since sold their stakes.