Mediabistro.com a Web Site for job-seeking media and creative professionals is sold for $23million. The Jupitermedia Corporation, an Internet research company that also sells photos and art, agreed to pay $20 million in cash and an additional $3 million over two years for the company. Employers pay to post jobs on the site, which also offers premium content to users who pay subscription fees. Last year, the site had 600,000 unique visitors.