Bluecore, a marketing automation solution focused on personalization, has raised $21 million in its series B round of investment.

The company has been growing quickly, adding $1 million in Annual Recurring Revenue (ARR) every 45 days, and doubling AAR every six months. A number of top ecommerce retailers are now customers, including Staples, Express, and Cabelas.

Bluecore lets marketers use behavioral data to personalize customer engagements, primarily via email. We’ve found in our own research that behavioral data is often the most valuable type of data for marketers. Behavioral data provides real-time insight about a consumer’s interest and intent, most of it coming from web and mobile activity.

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