Yahoo continues its shopping spree by buying the email and address book management app Xobni. It is the Internet outfit’'s third acquisition in as many days as it seeks to revamp its online products and boost its Web traffic.

Yahoo wants to integrate Xobni's technology into its communications products, including the mobile and PC versions of its email and instant messaging services. Yahoo did not disclose the financial terms of the deal which is probably worth about $40 million. Yahoo said that 31 Xobni employees will be joining Yahoo, including Chief Executive Officer Jeff Bonforte, who previously worked at Yahoo.

Earlier this week Yahoo bought Qwiki which makes an app to create mini-movies using a customer’s photos and videos and Bignoggins Productions, a mobile app to help players of fantasy sports teams. This follows the $1.1 billion acquisition of blogging service Tumblr last month.