Related-Links Blog Plugin Zemanta Raises $3 Million

Zemanta, a web add-on that injects blog posts and CMS articles with links to related material, has raised its biggest venture round so far in order to bump its sales efforts and product development.

The $3 million comes from existing backers Union Square Ventures and Eden Ventures, and nearly doubles its funding so far to about $6 million. We previously knew the company had raised about $2.2 million, including from Saul Klein’s The Accelerator Group.

Zemanta won Klein’s Seedcamp startup pitch competition in 2007, with Union Square’s Fred Wilson calling it “AdWords for content creators”.

But is there really a business in automating the addition of related links to blog posts?

CEO and co-founder BoÅ¡tjan Å petič writes: “Earlier this year, we started experimenting with what we call ‘promoted recommendations’. it really caught attention of large content publishers, so we will be investigating it further. We hate obtrusive banner ads and we know there are much better opportunities. We believe in ‘advertising as content’.” Å petič tells TechCrunch he’s serving a million recommendations per month.

Zemanta is now carried as a plugin in installs of and blogs, so it could get a slice of this “advertising as content” from two of the world’s largest blog networks.

Originating in Ljubljana, Slovenia, Zemanta has offices in London and New York.