For 12 years, Eric Ryan and Adam Lowry, the co-founders of Method, have nurtured their soap company's quirky culture. So when Ecover, a Belgium-based maker of green cleaning products, acquired Method in September, Ryan and Lowry celebrated in their own way.

At Method's San Francisco headquarters, Ecover execs got a pep-rally-style welcome, complete with music and a high-five tunnel. That was followed by a Belgian-beer tasting party and Belgium trivia.

"The first goal was to find Belgium on a map," Ryan jokes. "I've at least got that covered."

The combined company will have 300 employees and more than $200 million in annual sales. Ryan insists Method won't change much: He will keep managing product design, Lowry will focus on environmental sustainability, and Drew Fraser will continue to be Method's CEO. The major difference is that Method will now help distribute Ecover products in the United States and vice versa.

"Now we know how to start a company and how to sell a company," Ryan says. "We're just learning how to merge a company. Hopefully, we'll get it right and become a case study for the right way to do it someday."