Lack of American Heavyweight talent
Perhaps the biggest cause for the current lack on interest at least in the U.S market for boxing is the lack of credible American heavyweights.
Currently the major world titles are all held by European fighters and there aren't any American contenders on the horizon that look likely to change that situation in the near future.
That isn't to say that the heavyweight market as a whole is suffering.
The British, Russian and German markets in particular are as strong now as perhaps they ever have been, with former champions such as David Haye and current champions Wladimir and Vitali Klitschko regularly achieving impressive pay per view and live attendance figures.
While the American heavyweight scene remains stagnant however, interest in the U.S for heavyweight fights will remain low. The trickle down effect being that other fighters who perhaps might have been able to build followings on the undercards of marquee heavyweight fights in years gone by will remain anonymous to casual fans.
Due to the fact that there are a handful of powerful promotional groups that control the majority of the most marketable fighters in the sport today, many of bigger events these days tend to feature only fighters from one promoter.
Look at any of the biggest pay per view events of the last few years and it becomes readily apparent that the vast majority of the time marketable fighters are being fed lesser fighters signed to the same promoter.
Being able to fight only fighters signed to the same promoter allows the most marketable fighters to have the odds stacked more heavily in their favour from the beginning.
As the entire purpose of a promoter is to try to gain the best terms possible for their fighters, many view having both fighters in a particular bout signed to the same promoter as a conflict of interest, since the terms of any bout, eg ring size, purse split, glove type, will generally only ever favor one fighter.
The end result of this is that top fighters aligned to opposing promoters tend not to fight each other nearly as often. Each promoter preferring to give their fighter easier competition than risk them against a fighter that they have no financial stake in.
For the promoters, this is simply protecting their investments and makes sense. For the fans, this means that top fighters rarely fight each other.
A perfect example of this was the much talked about Manny Pacquiao vs. Floyd Mayweather bout that for one reason or another never happened.
Fundamentally however, despite whatever other reasons given at the time, Pacquiao was signed to Top Rank, while Mayweather was co-promoted by Golden Boy. Neither side really ever wanted to risk their fighter against the other due to the fact that a loss would have meant a massive hit to the losing fighter's marketability.
The World Title Issue
Although not an especially new problem, the amount of world titles in each weight class often makes for a convoluted picture of who the best fighters in each division really are.
As if the four major world titles weren't problem enough, fans new to the sport are now faced with baffling concepts such as 'Diamond' and 'Silver' championship belts, so-called super champions and interim champions, not to mention the plethora of lesser world sanctioning bodies each with their own world titles.
To make matters infinitely worse, because the various world sanctioning bodies are in most cases more concerned with collecting sanctioning fees than ensuring that the most deserving fighters get to fight for titles, in many cases the champions are nowhere near the best fighters in the division anyway.
Titles in and of themselves have then essentially been rendered meaningless, with any fighter with the right promoter or fan appeal being easily able to lay his hands on one.
The Changing Attitude of Fighters
There was a time many years ago when most fighters tended to fight whoever was put in front of them without worrying so much about what they were going to make or how hard the fight was going to be.
Certainly fighters have always to some degree picked their opponents or had their opponents picked for them by their promoters. Today however due to the amount of money in the sport and the financial advisers and managers that fighters tend to employ, many fighters are very picky about who they will fight and how much they will have to be paid to step into the ring at all.
In some ways this is a good thing as fighters who in yesteryear might have ended up with little to show for their efforts can now make a very lucrative living without ever having to be especially skilled or even marketable.
From a fans perspective however many intriguing bouts never happen because one fighter or another is unwilling to fight for less than they think they are worth, which in many cases is a ludicrously inflated figure compared to how much money they actually bring in for their promoter.
Far too many fighters today won't even entertain fighting for less than a million dollars, this despite the fact that they aren't champions and bring in very little in terms of either a live gate revenue or high viewing figures.
The Rise of MMA
From humble beginnings only a few years ago, mixed martial arts, spearheaded by the UFC, has developed from little more than a fringe sport into a valid competitor to boxing.
While the current demographics of either sport actually have relatively little cross over, the MMA demographic is much younger than boxing's. In the broader picture this means that boxing fans tend to be older than MMA fans and that MMA is attracting new fans and younger audiences. Over the long term this essentially means a possible huge reduction in boxing fans and growth in MMA fans, as new combat sports fans tend to be drawn to the latter rather than the former.
While boxing pay per views still tend to outdo MMA in terms of one off events, the majority of the top ten biggest pay per view events each year these days are all MMA events. A trend which looks to continue and might eventually mean that MMA eclipses Boxing financially.