PPC device-based signal location targeting...

In case you've missed it, PPC ad location targeting can now be selected by device-based location signals.
This is another good reason to have mobile landing pages specifically for separate mobile-specific campaigns.

You can now create a mobile-specific ppc campaign directing traffic to a mobile landing page,
reaching customers who are physically in the area of the business right when they are searching on their
smart-phones during dayparted business hours, so a quick response to a form lead or a click-to-call may result in an instant face to face appointment or sale.

This is also important for ppc relevancy because it allows the exclusion of people who may be searching with example 'Boston' in the search terms while not actually being in Boston.