'We will be doing business again, and I will be recommending you to people! Awsome job! Thanks'
'I just heard from my sister that the flowers sent to my brother in law arrived and looked beautiful. Thanks for the great work.'
'Easy to use, arrived on time for the funeral. I appreciate a site like this for those far away events in life. Thanks.'
You won't be able to dismiss this by usual means (escape or click button), but you can close it programatically based on user choices or actions.