Over a decade ago, I launched a short-lived community for community professionals (Commania).
I wanted people to upload photos of themselves so we could see who’s who.
One option would’ve been to relentlessly pester newcomers and offer rewards/points for completing profiles.
I figured this would’ve been more trouble than it was worth. So I took a different approach.
I set the default profile photo to a grinning pig (in hindsight, I might’ve used something else).
No-one wanted a grinning pig to appear next to their name when they posted a comment, so in the overwhelming majority of cases, people updated their profile photo.
In all the communities I’ve worked with since I don’t think I’ve ever had a photo upload rate as high as that community.
In short, there are many ways to change behavior if you’re bold, creative, and clever enough. Pestering and prodding members is the most common, but it’s neither the only (nor the best) option.