Why did it fail? There isn't any other low cost airline flying from the west coast to Amsterdam. And I saw loads of adverts for the route on billboards, Glasgow taxis, bus shelters etc so it's not as if the public weren't aware that Transavia were flying from Prestwick to Amsterdam. I'm sure that if there is a big enough low cost market from the west coast to Amsterdam then some airline will surely step in and operate the route either from Glasgow or Prestwick.