I keep going back and forth on DNI versus a single static number for local service businesses. DNI swaps in a tracking number per visitor, so you can tie each call to the keyword or landing page that produced it. The catch is that a site full of swapped numbers can make the number on your Business Profile and directory listings drift from the one people remember. For a plumber whose customers search the brand name and call whatever they saw on Maps, that can cost more than the attribution gains.
What makes sense to me is keeping the static number on the Business Profile and listings, and using DNI only on paid landing pages where the keyword data actually matters. Has anyone seen call volume drop after turning DNI on across the whole site?