I refuse to believe that Google can't pre-fetch ads and monetize their maps in other ways. Want your company logo to appear on the map itself? Pay up. I'm sure fast food chains and places like Starbucks would fork out to get custom pins.

Garmin has tons of map data too, and they "give it away" when you download it for your device. The offline mode might not have all the detail of the live version, but it could be good enough for travelling in remote areas without reception.