Jumpseating is supposed to be for personal travel or commuting to/from work. If there's a ticket authorized, you're supposed to spend the ticket money. If you're found to have been issued a ticket, but jumpseated instead, you could jeopardize jumpseat privileges for ALL of us! Don't do it. The pax carriers need every ticket dollar they can bring in. If you have to chip in some to make up a shortfall in the bank, do it.