According to an Associated Press article, the Raiders vs. Texans Monday Night Football game generated around $45 million dollars of revenue for the NFL and the Mexican economy according to a study commissioned by the NFL. Considering your average regular season NFL game generates in the ballpark of $10 million, that's the sort of number that makes eyes pop and dashes any belief that the NFL will not continue to hold games in Mexico for the foreseeable future.
Much of that figure was spent by tourists, as the game had well over 75,000 fans in attendance, most of whom came from the United States or other parts of Mexico.