Ginny Marvin says, “Bing Ads is testing changes to device bidding in the wake of Google’s move to revert back to distinct device bidding (though the bid adjustment structure remains) for desktop, tablet and mobile introduced in 2013 with Enhanced Campaigns.

Even through the Enhanced Campaigns period, Bing Ads had always offered more control with a tablet bid adjustment that could range from -20 percent to +300 percent from desktop. Now, tablets will be separated entirely from desktop. The top range for both tablet and mobile has been raised to 900 percent, up from 300 percent.

Desktop bids can only be set as low as 0 percent, so negative PC bid adjustments set in campaigns imported from AdWords will be set to 0 in Bing Ads”.

Bing Ads opens pilot for device bidding

Search Engine Land