A few weeks ago, we covered that Google added help documentation links to Place Actions but those help pages 404ed and returned no details. Well, now they bring up details explaining that Place Actions are for allowing searchers to interact with the local box to allow them to place orders, make appointments and complete reservations.
This is similar to what Google was testing with DemandForce early this year.
When you add the place action markup, your local result may add these actions, such as "book an appointment" as you can see in the image below:
The feature is currently a test and if you want to participate, you can fill out this form. Google explains:
When a user searches for a business on Google Search or Maps, users may see a prominent "Knowledge Panel" card with details about the searched-for business. Place actions will appear in the card and deep-link users to provider web landing pages or apps to complete their action with the business.
A deep link is a URL that points to a specific web form for a specific business from your inventory.
Here are the links to the documentation that was originally missing:
Forum discussion continued at Google+.