Forty-two is the answer to life, the universe, and everything, according the Hitchhiker’s Guide to the Galaxy. It is also the number of millions that hard-charging marketing automation vendor Act-On has raised in a significant fifth round of institutional capital.

“How fast we can grow is really about how much money I have to hire salespeople,” said Act-On CEO Raghu Raghavan, explaining what he plans to do with the money. “This is not a market where I have to fight competitors … marketing automation is still a greenfield market with only five percent penetration.”

Marketing automation systems help companies manage complex one-to-one marketing campaigns by personalizing web, mobile, social, email, and other marketing communications with both prospective and current clients. Act-On is a up-and-coming contender that hit VentureBeat’s list of top 10 marketing automation vendors. The company is based is Beaverton, Ore., and largely focuses on non-tech companies.

The $42 million funding round was led by Technology Crossover Ventures, with existing investors Norwest Venture Partners, Trinity Ventures, US Venture Partners, and Voyager Capital also participating. TCV’s participation is significant, as the company has plenty of experience in marketing technology and an investment thesis that is focused on putting large amounts of capital to work in maturing startups that have proven their worth and are poised, the firm hopes, for massive growth.