A great way to sneak a bit of marketing into a user’s post is to use an appended message with the email and twitter post options. What this will do is automatically add a line of text to a user’s message, so that the recipient of the photo will have a chance to read and act upon whatever message you append.
The appended message can range from a simple thank you for attending your event, or a call to action to make a reservation at your venue.
Since Foursquare has evolved and has temporarily been removed as a post option, the field for Foursquare has no effect.
Also note, appended messages DO NOT show up as visible to the user during the photo-posting process–not even when typing a message. What this means is the appended message will automatically be attached every time a photo is shared, and the user has no control over the appended message. As such, be sure your appended message is appropriate for the circumstances.