HGTV has launched a new online marketplace. It’s a place for small businesses to reach HGTV.com’s large audience, and a way for HGTV to make money from products mentioned on its shows.

The idea of aggregating advertiser inventory is a promising model for regional media Web sites, i.e., newspaper sites. Travidia and HarvestInfo, among others, offer these sorts of products. Unfortunately, it’s a hard sell because most local advertisers don’t have online inventory and online sales systems, so aggregating enough inventory to attract users is a problem.

HGTV, being national, shouldn’t have that problem.

But the regional model is a good idea just waiting for the right time.