The involvement of Cisco (CSCO) in this round is particularly noteworthy in that it shows the networking giant’s interest in marrying its content delivery systems with tools designed to measure the impact of the content being delivered. As paidContent aptly notes, this is exactly the sort of integration that led Adobe (ADBE) to acquire Omniture (OMTR) for $1.8 billion last year. Seems we have the beginning of a trend here.

To date, the company–which makes the leading open-source ad serving software, catering to about 30,000 Web publishers on 100,000 Web sites–has raised $30.8 million. “We raised $15.5 million at the end of 2007 and still had a chunk of that left, so we didn’t have to raise money,” OpenX CEO (and former Yahoo Senior VP) Tim Cadogan told The Deal. “But if it’s generally true that it makes sense to raise money when you don’t need it, in this environment, it is triply true.”

Quadruply true when you’re competing with the likes of Google’s (GOOG) Double Click and Yahoo’s (YHOO) Right Media, which dominate the Internet advertising market in which OpenX plays.