interesting numbers from LN-KGL
"We also learn that ISC had 3,260 passengers in January 2011 and 16,603 in August 2011. In other words it's 5 times as many passengers in August "
So 10 people a day in January and maybe 50-60 a day in summer
even a Trislander will be struggling to make money in winter with loadings like that - and I'd guess a Dash 8 would be marginal in summer