Yahoo has acquired an app analytics firm, Flurry, to help boost its advertising revenue from smartphones.
Flurry helps app developers analyse data about their users and deliver more personalised ads to them.
Some of Yahoo's rivals have also bought mobile advertising technology firms in an attempt to lure marketers to their apps, as well as generate revenue from ads on other company's apps.
The two firms did not disclose the financial terms of the deal.
However, some reports indicated that Yahoo paid between $200m and $300m (£117m and £ 175m) to acquire Flurry, making it one of Yahoo's biggest acquisitions since it acquired blogging platform Tumblr in 2012.