You can adjust tracking sources to track either the first way that a visitor came to your website or the most recent way.
First Touch: The first time the visitor came to your website
Last Touch: The most recent way the visitor came to your website.
When would you use First/Last Touch?:
By default we have the first touch on. This will allow the people who come to your page to always see the same phone number. Sometimes people want to know if the money they spend in ads will convert to a call so in this case you would turn last touch on for any paid sources.
If you want to know always the most recent way your visitors come and do not care if they see the same phone number or not you can turn the last touch on for all of your tracking numbers.
Where to Change to Last Touch:
Go to Numbers then to Tracking Sources, Check the last touch to have last touch activated.