This sounds like Brighton City airways MkII.
Solent Airport! ... The BIG reason why SOU is successful is because it has an airport rail station on a line from London, I don't know the stastics but a LOT of it's passengers shall be arriving/departing by train and not originating necessarily in the SOU area, just compare SOU and BOH figures, SOU has a rail station, BOH doesn't.
Lee-on-Solent on the other hand is about as remote as it is possible to be, passengers can fly to GCI, to then take a quickie connection to ACI, from pretty much anywhere in England, why on god's earth would they want to drive all the way to/from Lee-on-Solent to fly on an Airfix kit?
And as for Shoreham-by-Sea, JEA (aka Flybe) couldn't make JER work with Twotters, Brighton City Airways is another story and now Air Alderney want to fail also.
I'll give them about the same, perhaps slightly longer, life expectancy on these routes as BCA on their Beauvais route ... that I don't recall ever made it to Beauvais!