you forgot about income taxes, the government always has to get their cut
685 x TWO x $40 sign ups per day then -
overhead bandwidth promotional costs to support the number of sales you are generating
+180 x $40 per day
then the cost of owning the yacht, moorage, maintenance, etc (10% per year)
+140 x $40 per day (x2 to include personal income taxes)
then the cost of the crew, say 5% if you were a cheap skate and hired starving workers
70 x $40 per day (you don't think those sails go up and down by themselves do you?)
then if you fueled up 10 times per year 10x5000 gallons x $2.00
Would you be having your food catered, or are you hiring a professional chef to run the kitchen?
Too bad for all those stupid sails, or you could have your helicoptor fly you back and forth to burger king for snacks