Softbank Holdings has signed a letter of intent to acquire an equity stake in Interactive Marketing Inc., a Los Angeles-based interactive marketing and communications company. Terms were not disclosed. As part of the deal, Softbank subsidiary Ziff-Davis Publishing and Interactive Media Sales (a division of IMI) will jointly represent a handful of sites on the Web, including Fodors, Hollywood Online, Playboy, NBC, Yahoo! and ZD Net. Additionally, Interactive Marketing will license a number of its trade shows to Softbank Expo and Conference, including its popular WebInnovation show.