Yahoo is embarking on a pilot program in which it sends graphical advertisements to mobile phones and other wireless devices, testing the effectiveness of brand advertising on small screens. The ads, 150x21 pixels in size, will be delivered to users of Yahoo's Mobile Web service.
Yahoo previously began testing text advertisements on phones in the United States and the UK. Wireless devices have traditionally been limited by slow speeds and high bandwidth prices, making graphical ads an expensive proposition with a limited audience. But as speeds and devices themselves have improved, more consumers are turning to their phone to look up information on the Web.