Nevada is mostly desert with vast strands of land people do not inhabit. They rely on mines, the US government, and being next to California for their money. Area 51 for example. The Yucca Mountain Nuclear Waste Repository as another.
California in the past banned gambling so that is how Las Vegas got started. As far as I know now you can only gamble in the state lotteries or on Native American reservations.
They are also trying to do the Delaware thing and be a place for corporations to incorporate in. Many states charge franchise fees and income taxes on corporations. Nevada charges nothing except yearly filing fees. Last I checked Microsoft chose this state for their legal headquarters.
Local jurisdictions levy taxes on property and sales.