Two generically positive compliments (e.g. 'You're cool!' (not a real example)) A couple of items where someone I work with felt the form was the best medium by which to give some work-related feedback — they did actually de-anonymise, but it gave them a place to put their feedback which was a) accessible to nobody else and b) unobtrusive & didn't immediately prompt a conversation. One person said words to the effect 'I thought you did a good job at [x public event where they saw me]' One person commented on my social presence, in a slightly off-beat way that I think would have been hard/unlikely to say in person. One person commented on someone I follow on Twitter.