I read recently that overseas Google Maps/Places is getting some companies up to 50% of their business. And of course we follow the USA so I believe it will come here very soon.
Nowadays if your Google Maps is optimised correctly you can get first page rankings for your targeted keywords way before your website will be ranking for this.
Also, with Android devices now having Google Places installed by default the benefits of Google maps listing increases all the time.
Many of our clients have shown a 40% increase in traffic just through optimising their Google Maps/Places listing correctly.