Which user characteristic may NOT be used to change keyword bids in AdWords?:

Bid adjustments allow you to show your ads more or less frequently based on where, when, and how people search. For example, sometimes a click is worth more to you if it comes from a smartphone, at a certain time of day, or from a specific location.

In this article, you’ll learn about the different types of bid adjustments and their requirements, how multiple adjustments interact, and what options are available for different types of campaigns.

If you’re looking for instructions on how to set bid adjustments, read how to add or remove a bid adjustment.

How bid adjustments work

Bid adjustments are set by percentages.

Say you’ve got a campaign that performs well on mobile devices with a max CPC bid of US$1. To show your ad to more customers on mobile devices, you increase your bid by 20% for searches on mobile devices, resulting in a final bid amount of US$1.20. Here’s the math:

Starting bid: $1
Mobile adjustment: $1 + ($1 x 20%) = $1.20
Resulting bid for searches on mobile devices: $1.20

In another example, let’s say you have a US$1 bid and would like to decrease it. To adjust it to US$0.80, select Decrease by 20%.