A recent report from Hitwise finds that traffic to online classifieds soared in the last year but notes that search engine optimization (SEO) gives the providers even more opportunity for growth.

According to the Hitwise report, visits to online classifieds increased 84 percent from February 2008 to February 2009, with the majority of the growth coming from Craigslist.

But the report also points out that these sites have generally received little traffic from search engines, which means the potential to use search engine optimization (SEO) and keywords to increase quality leads for these sites is great.

In February Craigslist Cities received only 10.86 percent of its visits from search engines, according to the report. Hitwise says part of the reason for this low ratio of traffic from search engines is people’s familiarity with using the Craigslist parent site.

However, the site does appear to be benefiting from long tail searches.

"In the four weeks to February 28, 2009, only 9.93 percent of search terms sending visits to ‘all other classifieds’ were one word search terms (such as ‘bicycle’ or ‘apartment’), compared to more than a quarter (25.04 percent) for the ‘shopping and classifieds’ category as a whole," says the report. "By contrast, 28.80 percent of queries sending visits to ‘all other classifieds’ contained five or more keywords, nearly twice the share as for the ‘shopping and classifieds’ parent industry."

A report last month from Hitwise found that internet users are increasingly using five or more words in average search queries. Between February 2008 and February 2009, searches that were five words long or more increased 9 percent, while searches four words or shorter fell 2 percent.