Quantcast, a San Francisco-based web analytics company, says it has raised $27.5 million in Series C funding. Cisco Systems is leading this round of funding which also includes funds from previous investors Polaris Venture Partners, Founders Fund and Revolution Ventures. Quantcast by now has raised close to a total of $50 million in funds. It has built up a massive infrastructure that allows it to measure digital audiences. I’ve always liked this company — its Quantified reports are more meaningful than some of the arbitrary numbers thrown around by other last-generation measurement services.