'Ordering was easy. Thank you.'
'It's is the first time I use this company and I have to tell you service was extraordinary. Thank you from the bottom of my heart it meant a lot to me that the arrangement get delivered on time.'
'Just talked to my sister and my mother received the flowers and the arrangement is beautiful. Thanks so much for the flowers and the very good service!'
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.