How to measure the success of an SEO campaign for restaurant/bar/bakery type sites

Hey guys I’m just wondering what kind of benchmarks you guys use for say a restaurant. The client wants deliverable results, high traffic is not and should not be enough. So what kind of metrics can I put into place besides keeping track of analytics and stuff? Should I get a baseline measurement of say, reservations made? I mean obviously it would be much easier if they used something like open table but what if they don’t? What if they just want a simply reservation button or if they just have a “call this” type text? Any input would be greatly appreciated.