As far as I know, you need an onward or return ticket to get into Aruba.
Does anyone know if an onward ticket to Bonaire is sufficient?
Or does the ticket has to be out of Aruba and the Netherland Antilles?
you should contact aruba imigration
or maybe the airlines can answer the question
my guess is that they want to know you are not staying "forever"
Well it turned out I didn't need an onward or return ticket. They didn't ask for it. Probably cause I have a Dutch passport.