PopularMedia, a developer of social media marketing tools, has raised an $8 million third round led by DAG ventures, along with past backers Sequoia Capital and Steamboat, reports VentureWire, via VentureBeat. The company raised $4.25 million last year, though its totals haven’t been publicly announced. Offerings include tools to make content go viral, or to let any site offer the ability for users to find friends from their email’s address book. The SF-based company’s latest product is SocialNotes, a comment and feedback widget.