Do you make any money off your novels?

I had always pictured novel writers as making a lot of money so it was shocking when Larry McMurtry said in his literary work that he never made much money off of his books, even Lonesome Dove.  He made most of his money off of the screen plays.

My sister has had 17 christian books published.  Most were novels, but a couple were nonfiction.  She has made a little bit over the years, but not enough to bring in any real income.

My brother-in-law has written 3 very good westerns.  Since he had them published himself, according to my sister, they actually cost them money.  He told me that he gets a small amount from them from time to time, but will never break even.

I guess there are some of the more famous writers that make a actual living out of writing novels, but there are probably not a lot of them.

So if you are a novel writer, have you made any money off of your novels?