I do this at work and now I can put a name to it :)
Its something I deploy to low-stakes instant messaging communications. So you might get a:
'Hey quick one can you help with <request>'.
I can see the request but defer acknowledgement.
If its low-stakes then I sometimes leave it for 15 minutes and then acknowledge it up and its amazing how many times I do that I get a:
'Ahh no prob, sorted it out'