I haven't heard much talk about this, but in the recent world first kill of Azshara, Method (that's the amazing raiding guild), were watched by almost 200,000 viewers as they brought her to heel. While much of the buzz surrounding this kill was helped by Method's rivalry with Limit, there were a fair few guilds in contention for the world first, European guild, Pieces, were in the mix, most folks were convinced Method would run away with it. Sure enough they did, and a huge swathe of players were there to watch it. 

I think what's particularly interesting about the data given by EsportsStats, is that it not only demonstrates that WoW's raiding scene is very much alive and well, but that it's incredibly enjoyable to watch. It makes me wonder whether there would be value in Blizzard creating smaller raid encounters (maybe one or two bosses), but ramping up the difficulty significantly in order to create brief, but super challenging encounters. The idea being that there's a constant delivery of raid-like content, to continue to grow this viewership. 

Either way, such "events" are great for World of Warcraft and Blizzard; long may it continue.