Internet Brands, the publicly traded holding company for a sprawling number of unrelated websites, has added five new ones to its portfolio. Two of them are focused on high-def stuff: HighDefForums.com, HighDefDigest, while another, AVRev, is on general audio/visual stuff. The largest site of the bunch is FitDay.com, a fitness site, while another, VetInfo, focuses on pet health. The LA-based company tends to announce these purchases in big clusters. In February, it bought nine sites, eight of which were auto focused. Terms of the acquisitions were not announced. Release.