whoever is running tennis should take a look at golf. Golf tech is constantly changing but they have limits on what is acceptable. From the clubs, how "hot" or how much rebound the clubface can be, to the balls spin etc. Tennis has failed in this department. It's pretty much has no limits except racket head size/length. The sport does seem very popular to me and growing (maybe more with the city I live in) but I don't have metrics to see if the game is growing in the US, globally etc. I do know golf has far outpaced tennis in terms of popularity (mostly due to tiger) the money, sponsorships, junior programs, tv deals etc have grown so much bigger. I'm not sure I can the same for tennis. I enjoy watching tennis because it's something I've watched and participated as a kid. If I didn't play as a kid there is no way I'd find the current tennis interesting enough to watch. I find watching a guy like Haas infinitely more exciting than watching Murray or Novak.