MailChimp is a marketing automation platform and an email marketing service and a trading name of its operator, Rocket Science Group, an American company founded in 2001. MailChimp began as a paid service and added a freemium option in 2009. Within a year its user base had grown from 85,000 to 450,000. By June 2014, it was sending over 10 billion emails per month on behalf of its users.
As a podcast advertiser, MailChimp also sponsored the launch of Serial, a podcast exploring a murder case over multiple episodes. During the series parodies of Serial have targeted several of the show's aspects, including the podcast's sponsor (especially the meme "MailKimp").
In 2016, MailChimp was ranked No. 7 on the Forbes Cloud 100 list.In August 2017, It was reported that, MailChimp would be opening its office in Brooklyn and in Oakland, California