Lijit, a popular service that lets blogs add search functionality, has raised a $7.1 million third round led by Foundry Group. Past backers Boulder Ventures and Colorado Fund participated in this latest round as well. The Boulder-based company has previously raised $4.2 million, for a total of $11.3 million. In addition to a simple site search, the company develops other search-based widgets, such as ones that can recommend certain articles to readers, based on how they came to a particular site. Of course, with the funding comes the responsibility to start making money from blog widgets (a tall order), so the company is also launching a new ad network that will allow publishers to sell ad inventory against their own site searches. It will also use the funding to expand its office space and employee base. Earlier this year, Lijit acquired BigSwerve, which specializes in searching comments. Release.