A lot depends on
when the person cancels. In one sceanario, it may be a "no harm, no foul" situation where the points just go back into your account with plenty of time to re-use them. In that case, you have lost nothing but a little time. You may also have a great deal of flexibility to "work out" the renter's vacation plans to both of your benefit. In a different sceanario, however, cancellation could mean certain loss of the points.
As Doc has pointed out, it is very important that both parties have a crystal-clear understanding of what the groundrules are in a rental. Whether you do that with a contract, or written "policies" or just by telephone, it is critical that the person renting the points understands how
you work in renting points. There is no standard practice, and every rental is different. Having that clear understanding is especially important near the end of your use year, when any problems are magnified by the approaching expiration of points, or in any situation where you have borrowed points for the ressie.
As Pam said, many vacationers renting points approach these transactions as "just another hotel reservation." If you don't tell them different, they think they can cancel by 6 PM on arrival date with no repercussions to either you or them. They're not bad people trying to cause you problems, but they're not psychics either.
A much more appropriate comparison to a
DVC rental is renting a condo at an exclusive ski resort. There you pay a deposit up front, and usually have to have paid in full 90 days
or more prior to arrival -- often six months prior. There is no cancellation. If you feel you need
trip insurance to protect your investment in your vacation, you buy it. I would encourage any renters to protect their own vacation investments however they see fit. That's their responsibility, not the
DVC owner's.
I think it is also important for owners to approach rentals as purely business transactions. I've seen a number of posts from owners who suffered cancellations and took all or part of the loss because they felt sorry for the person who had to cancel.
That's your call, but it's not very sound business practice...and it's also not fair to
your family. In fact, it's a practice that just perpetuates the notion that people can cancel with no consequences. I would certainly do everything I possibly could to help a renter who encountered a problem, but I would not take a loss due to their cancellation.