I got these free from 3M and just in time for an off-site Corporate Initiatives meeting between managers and executives. We were able to put these on the walls, write on them with sharpies (no bleed through), and then stick 3x3 Post-Its to them. This was 3 weeks ago and they have survived riding around in my truck for 4 days after the meeting then sitting stacked on my desk for a week, then re-posted to a conference room wall for a day, then moved to my boss's office where they have been for about two weeks (Without falling down!!!) Every little Post-it still where it belongs (and they were moved around several times). [This review was collected as part of a promotion.]