Blackarrow, a heavily backed developer of dynamic cable advertising has raised a big $20 million second round from past backers Cisco Systems, Inc., Comcast Interactive Capital, Intel Capital, Mayfield Fund and Polaris Venture Partners. The company has previously raised about $18 million in two parts of what they’re calling just one round, for a total raise of $38 million. The San Mateo-based company develops un-DVR-able and targeted ads, designed to account for changing viewing patterns. It says it will use the money for the standard stuff, product development, rollout and sales. Some more details in release.

Interestingly, Comcast is also an investor in the high profile Canoe Ventures, the cable co-JV that is also in the targeted cable advertising space. Also, other competitors include the likes of SpotRunner, Google, and others.

• Ad-Insert Startup BlackArrow Raises $12 Million Second Round; Adds Comcast
• Ad Insert Start-up BlackArrow Raises $14.75 Million For Unskippable Ads