Tumblr has introduced sponsor packages for advertisers in its first attempt at generating substantial revenue. Packages, which start at $25,000, get advertisers access to Tumblr's 120 million daily impressions through prime spots on Tumblr Radar, which features the site's most popular posts, and Spotlight, a curated showcase of creative content. The company has no plans to require users to host third-party ads on private blogs, Tumblr tells Fast Company. "Users can host ads on their own if they wish," Tumblr spokesperson Katherine Barna says. The outlet is already a favorite of brands such as Coca-Cola and Calvin Klein, but Tumblr has resisted advertising since its inception—founder David Karp told the L.A. Times in 2010 he would rather sell the company's desks than resort to advertising.