40,000 seat stadium 81 times per year, or at least put 28,000 seats in a stadium per game (the median average). Las vegas is the 30th largest metro area in the US. This would put vegas near the bottom ahead of Milwaukie, cleveland, kansas City, cincinnati and Pittsburgh. That's not terrible, but its not great either. the difference though is that none of those cities have four professional franchises and all of those cities are located near numerous other metro areas that contribute to the franchise's population base. Las vegas has nothing. Maybe St. George would qualify, but it seems like people in St. George prefer to identify with Salt Lake teams over Las Vegas (that could change in the future),

TV market is also huge for revenue. Unlike the NFL, MLB relies on local tv money for its own revenue. As the 39th, Vegas would be the smallest tv market in the majors.

Overall, I don't think Las Vegas is a terrible destination for an MLB team, and it might be a very good destination for the NBA. I just can't imagine it being better MLB destination than anywhere in Northern California.