After the past month of boxing venues and UFC venues, on the surface it would appear that boxing still holds the crown as being a top draw.
Let's go a bit further though, boxing has maybe 1 or 2 huge matches a year. The weight classes are all chopped up from middle weight, light middle weight to fly light weight. Each weight class has at least 3 divisions, what's the point of that? Add to this the "Alphabet Soup" of sanctioning bodies that exist within boxing, IBA, IBO, WBA, WBO and so on and so on. Finally add the corruption allegations, fixing fights and contract strong-arming that has been alleged/proven at times over the past few years.
Jim Lampley is one of the outspoken announcers who says (I'm paraphrasing here) - Boxing is still king and is better at pulling the bigger paydays than any MMA venue.-
Fine I'll grant him that, but when you only have 1 or 2 big fights a year you can't help but have a big payday.
With MMA and namely the UFC, there are fewer weight divisions so there is a consistent parade of athletes that the audience is aware of and they don't have to know 30 weight classes. Much more fan friendly in this respect. They have matches about once a month, do a great draw on pay-per-view and audience seats. Depending on the fight seats are going from $2,000 to $10,000 in the lower arena near the ring. Not a bad draw considering they do this about once a month and consistently sell out the arena.
Then there is the reputation, the founders and enforcers for UFC and most MMA venues there are rules, and penalties. Pretty cut and dried about fighting and what is or is not allowed. They have worked hard to keep the sport "clean" and attractive to its audience. Purses are smaller, but title fights are more frequent, matches are on the surface more "evenly matched" due to weight, size and record. Matches might go quick but they are riveting, exciting and entertaining.
Overall UFC/MMA takes the cake, based on providing more consistent entertainment, match-ups and a "clean" reputation. Being more in-tune or having a grasp of what its audience is MMA venues know what they are doing. Boxing is grasping at straws and throwing out names to just make it somewhat appealing.
Give boxing another 5 years of this lack-luster approach and UFC/MMA will overtake it and the big paydays will be the only appealing thing about boxing.
Just my take on things.