Google has launched click-to-message ads. Click-to-message ads are ad extensions that, when clicked, open up the user's messaging app and allow the user to send a pre-populated text message to the advertiser. Advertisers can then have a text message conversation with the user, something that Google hopes will help advertisers reach a whole new segment of mobile-centric users who want the convenience of text messaging in their own time or whilst on the move. In order to use click-to-message ads, you need to have a phone number that is capable of sending, receiving and processing text messages. You will also need to write the initial text message that will appear in the user's messaging app when they click on the ad. You can set up message extensions in your AdWords account, setting them to apply to an ad group or an entire campaign. You will be charged on a per-click basis, whenever someone clicks on the message extension icon.