One of the components of our upcoming Devlearn "Ukulele Learning" sessions is some conversation around motivation and reward. A great example is happening right now in the DevLearn conference app, available to attendees. There's a swag shop with stuff like fun tshirts and sunglasses; app users can earn points toward purchases as outlined below. Notice the relative value of posting and filling out evaluations compared to just checking in or tagging something.
There aren't limits on what can be posted; everything doesn't have to be "work related". Many posts are about sessions participants attended today; some are from presenters sharing tidbits from their upcoming presentations; some are pictures of the hotel pool, quick meetups, or pets and kids left at home. There's a lot of fun and engagement and people are making new friends. That's important when you're at a conference, especially alone, and helps to sustain engagement beyond the event.
All behavior is purposeful. There's a great lesson here for those wanting to encourage use of collaboration tools and those who have goals like seeing more completed evaluation forms. I hope attendees recognize the app's activity feed as itself a valuable conference takeaway.