'Amazing job and thank you for getting the beautiful bouquet there on time.'
'Let's just say I will only use this company from here on out!'
'I really appreciate the quick service on the flower order. The arrangement was beautiful. Thank you for you services. Will use whenever the next need comes around.'
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.