New York--Media Metrix Inc. said Tuesday that eFront Media Inc. powered into the top 20 trafficked Web sites in July, and that directories surged more than 16% in usage for the month. Costa Mesa, Calif.-based eFront Media is building a series of vertical content hubs designed to attract audiences with content, commerce and communication services. Though primarily a consumer company, It includes a b-to-b site in its arsenal. Media Metrix, the New York-based research firm that uses audience panels to gather its data, said eFront broke into the top 20 traveled sites at No. 18 with 12.4 million visitors in July. The increase in directory traffic is of significance to b-to-b marketers because such advertising services as B2BWorks are concentrating much of their resources to listing advertisers in a wide array of b-to-b directories. The top five domains for the month were AOL Network, Microsoft, Yahoo!, Lycos and Excite.