Online commercial real estate marketplace LoopNet Inc. (NYSE: LOOP) has acquired for $15 million. Privately held distributes commercial property listings to more than 100 partners, among them the Web sites of large circulation daily newspapers such as the New York Times, Boston Globe and the Atlanta Journal-Constitution. Before the deal was announced, Cityfeet had 100,000 property listings on its site — or a fifth as many of the roughly 500,000 listings on the LOOP site. The deal will bring commercial real estate’s largest online marketplace and largest distribution network together, according to LOOP. LoopNet averaged 950,000 average monthly unique visitors during the second quarter, according to comScore.