Good news that the diversions chose KIA, but this was a one off and totally exceptional event.
I would wager that not one of the the flights which did divert would ever be considered as a regular operation to/from KIA.
It would be great if Manston makes a success of the forthcoming summer season, but nothing should be construed from the events of last week as regards the future success of Manston, no airport makes money by waiting for diversions.
That's commercial reality folks.