Question: So, in my Post-Apocalyptic world, there’s a city down in South Nevada known as Vegas. Unlike the rest of the majority of North America, Vegas was not hit by nuclear warheads in its near vicinity. But, over the last 100 years, society in the city has devolved considerably. 

Vegas lives in a state of near constant anarchy. The only government-like forces are the families, but they often cause more trouble than they stop, causing gang wars in the streets and political assassinations and such. Mostly, Vegas’s economy consists of prostitutes, gambling, and drugs. 

Back far west, in the region of New California, the USC (United States of California) has arisen, and now boasts a large army and strong government. But, like the Vegas of old, these inhabitants, especially the crime families, want tourists, mainly Californian tourists, to come to their city, as they bring valuable currency that can be used to buy more weapons and armaments. 

So, my question is, how can you market an anarchic city as a tourism spot to people (mainly people living in civilized government)?

Answer: 
Do you have a genuine **anarchy** or is it more a tribal or organized crime setting?

* The "families" do not want any city government to interfere with their business.
* The "families" want to do business with each other, so in the absence of law they must gain a *reputation for keeping their word*, and for punishing betrayals.
* The "families" want tourists to spend money.

So they put the word out, first within the family and then on the street -- anyone who touches a tourist without explicit permission from a family boss will **suffer**. Not for breaking the law, but for costing the family face.

Tourists might still be at a higher risk than in a truly law-abiding town, but to balance that they can buy all the sin they want. The rules don't protect the locals, unless the locals have family connections. In your setting, kinky demands are a matter of price.
While anarchy can be an impediment to tourism, it does not have to be if

a) Outside society possesses resources to protect themselves while visiting (i.e. the rich hire bodyguards they bring with them). If the nearby established government does not provide adequate internal security, this is likely the case.

b) Bodyguards are for hire within the city. Any tourist who is wealthy enough will hire one and those that don't will bring their own forms of protection. If someone is too stupid for either of these, then they likely get killed or robbed. This would not impact tourism because the thought is that those killed "had it coming."

c) There is something worth the danger to attract people. Being avoided by nukes, Vegas likely already has this quality. If it did not, the reputation of Vegas is such that people would come if prostitution, drugs, and gambling is still available. This is especially true if the nearby government outlaws or restricts any of these things. 

d) People can get to the city. This does not need to be caused by any of the families efforts, but can be from outside agencies.

Any of the families can promote one or more of these things to attract tourists, and if these things already exist, the city may have tourists without any effort on the families' part. 

However, a family could sabotage the tourism industry by targeting tourists and tourist bodyguards specifically.