Have you noticed that some Facebook applications let you “try before you buy”? In other words, these applications allow you try them out before you have to give them access to your profile.
The usual flow for adding a new application in Facebook goes something like this: You find an application, you click on “Go to Application” and then you’re asked to give the application access to your profile. Once you click on the “Allow” link, you’ve given the application permission to access your profile information, the application has been added to your application list and you’re taken to the application dashboard or main page. Some applications, however, take you directly to the application dashboard or main page and you are only asked to give the application permission to access your profile if you wish to engage in some action with that application.
As you can see, there are only two steps: 1. going to the application and 2. being taken to the main page of the application.
This allows the visitor to see what the application is about before they give it access to their profile (some more cautious users may be weary of giving an application access to their profile) and since visitors are only asked to give the application access to their profile after they’ve decided to engage with the application, it may increase your chances of converting a visitor to a user.