For those expats who are undecided about what kind of business to start, franchises are a good option. While there are pros and cons to opening a franchise anywhere in the world, opening a franchise as an expat gives you the systems and guidelines you need to make the business work. Another very important point is to watch the trends in the United States and Europe because Mexico tends to adapt the same trends several years later.
Here's an example:
At the beginning of 2005, a frozen yogurt chain called Pinkberry took Southern California by storm. People were lining up to get their hands on the yogurt and soon after Pinkberry had a cult like following. Other chains followed - RedMango, YogiBerry, etc.
The point here is to always be looking for trends in other countries because most likely, sooner or later those trends will become popular in Mexico. It is crucial to analyze the franchise and see if it really fits into the Mexican culture. Another good way to get a gage on what could be successful is to look at where Mexicans who travel are going when they are abroad.
Here is a link to Mexico's Franchise Expo (franchises from around the world).