Asking if Las Vegas makes money on filming is like asking if Las Vegas makes money on gambling. Las Vegas makes money on everything it does. And in this case, it's big money.
A number of factors make Nevada attractive to film crews, including the dramatic geographical diversity (you've got everything from Vancouver look-alikes at Mt. Charleston to Martian landscapes at the Valley of Fire, not to mention Lake Tahoe and the Strip, among other options). The good climate and reliable weather, a lack of red tape, and the relatively low cost of living are also factors in the state's favor. Most public property is free to film on (although you do need a permit). Private properties often charge location fees, based on the size of the project and how intrusive it is. But the main source of revenue is from the amenities and local resources that an out-of-town crew uses while it's here: accommodation, food, vehicle rental, equipment hire, local crew and extras, production facilities, entertainment, etc. Those figures can really mount up.
The Nevada Film Office, which falls under the auspices of the state Commission on Economic Development, reports revenues based on visual-media production for the whole state, not by area. Statewide, the numbers are as follows.
In total, television, film, and still photography pumped $102.5 million into the Nevada economy in 2005, the sixth straight year these media broke the $100 million mark in revenue.
The biggest gross comes from televison series and specials, which boosted state revenues by $39.3 million. Reality-TV programming added $10.3 million, commercials $9.8 million, and music videos $2.9 million.
Sixty-four films were produced, at least in part, in Nevada in 2005, for a total economic impact of $18.2 million.
Still photography accounted for $10.1 million.