A mobile bid adjustment is as a percentage increase or decrease that is applied to normal Costs Per Click (CPC) bids with the intention of winning coverage on mobile devices.
It’s fairly easy to set up an AdWords account by picking various keywords, selecting a decent bid as suggested by Keyword Planner, and immediately start generating traffic on Google desktop. This is purely because there is a lot of real estate for adverts (up to 11 ad slots) on that platform. It’s not so simple on the mobile platform. The experience is very different because mobile devices have smaller screens and therefore fewer adverts are served for any given search. Current AdWords bids may be winning coverage/clicks from desktop customers, but fail to win on mobile.
This is why Google developed mobile bid adjustments which help level the playing field. Setting a mobile bid adjustment enables advertisers to reach users searching from their mobile devices. The mobile opportunity is huge. According to a study conducted by comScore mobile usage has surpassed desktop usage as the most used digital platform.

Research conducted by Google reveals that more than 38% of our daily media interactions happen on mobile devices. The report shows that mobile devices have the highest number of user interactions per day and thus advertisers need to tap into this mobile atmosphere if they want to reach potential customers. Let’s take a look at two very different customers – Lerato is searching on her mobile device after work and Dumisani is searching on his desktop computer from home

They are both searching for Pizza, and see an advert from a local pizza parlor Hiltons Pizza Parlor. For Dumisani’s search on his desktop computer, our ad appears in the 2rd or 3rd position on the page and he decides to click. However for Lerato, fewer ads appeared on her mobile device’s screen and is not exposed to our offering. She clicks on one of our competitor’s ad, places an order and collects it on her way home. Our adverts were never seen and we lost money. Our adverts might have been seen by Lerato if we had increased our bid on mobile devices by 15-20% – and thus win both orders. Mobile bid adjustments enable us to do just that. If our current bid is R20 we could then adjust our bid up by 20% to R24.
Please note that Mobile bid adjustments are only available for “All Features” campaigns. The adjustment is a percentage increase, not a rand amount. For example, if my bid is set at R10 and I add a 15% bid adjustment, then my bid for users on mobile devices would be R11.50.