Self-service online marketing firm VerticalResponse, an Inc. 5000 honoree since 2006, has acquired social media start-up Roost. Terms of the deal were not disclosed.

The acquisition will allow small businesses to "create, schedule, manage, and measure their social media marketing campaigns" on Facebook and Twitter, Vertical Response said in a statement.

Roost's services also will make it easier for users to "build and manage engaging customer relationships." The company offers pre-fab campaigns for a range of industries that can serve as conversation starters for customers on Facebook and Twitter.

The number of VerticalResponse customers sharing e-mail marketing campaigns with their social networks increased over 1,400 percent in the past year, according to CEO and founder Janine Popick. The company's flagship product is its bulk e-mail delivery service.

Vertical Response, founded in 2001 and profitable since 2005, has grown 150 percent in the past three years. The San Francisco-based company has nearly 100 employees.

Popick told Information Week she discussed a partnership with Roost but that buying the company made more sense.

"We concluded this could be really core to our offerings, and we needed to take it one step beyond a partnership," she said.

Said Roost CEO Alex Chang: "We realized we were servicing a lot of the same companies with the same kind of products." Roost's website now reads, "Roost by VerticalResponse."

Roost services are free for now, though the four-year-old company, also based in San Francisco, has plans to introduce add-on services that will cost $10 to $40 per month. That will still happen, though the timing is unclear.