Eurogamer has a nice WAR beta review, in which they mention that they didn't test all that much RvR, because they couldn't find enough other beta players around to even start a scenario. I'm in several betas at the moment, including WAR, WotLK, Football Manager Live, and Wizard101, and I noticed a common trend: Lots of people online when the beta opens up, and then rapidly dwindling numbers. Why do so many people who join a beta end up not playing it very much after a while?
The first thing we need to get out of the way here is an illusion: Lots of people will tell you how lucky you are if you are allowed to play in a beta at all, and that beta testing is all about helping the game company to make a better game. It is actually surprising how many people on the otherwise rather cynical internet hold this idealistic belief. The reality looks rather different: A beta is a deal between the game company and the beta testers, in which both sides get something out of it; typically the game company gets some free server load testing and bug hunting done, while the beta tester gets to play a game for free, and before everybody else. People don't beta test out of idealistic reasons. I mean, you could probably help Mythic or Blizzard by volunteering to do unpaid janitorial work and clean their toilets for free, but who would you expect to do THAT? People join beta tests to get something for themselves, not to perform unpaid work out of idealism. So if we want to understand why people leave betas, we have to understand what their motivation was to join in the first place.
One reason to play a beta is to play a game for free, which later will cost something. This is often done with the added motivation to see the game before paying for it, in order to evaluate it. If you played the beta for a while, you probably have a much better idea whether you want to buy the game or not. Taking that decision usually doesn't take weeks, so this is one reason why people stop playing a beta quickly. Decision made, motivation to beta test gone.
People even stop playing the beta if they decided that they will play the release version of the game. One factor here is that playing the beta isn't quite as pleasant as playing the release version: Betas by definition have more bugs, more server downtime, and in many cases frequent character wipes. Pretty much every beta does a character wipe a few days before release, so that in the release version you either start from level 1 again, or only get a few days head start if you pre-ordered the game. Why would I want to, lets say, level a copy of my level 70 character to 80 in the Wrath of the Lich King beta, if I'll just have to level that same character again from 70 to 80 in the release?
But there are some things you can take out of a beta into the release version, and these constitute another motivation to play the beta in the first place. One is knowledge about the game. For example I used the WAR beta to decide what character class I want to play in the release version. As beta characters don't last, it's a good opportunity to make many alts and see how they play, and which ones you like. In games where you compete against other players, like in Football Manager Live, knowing how the game works gives you an advantage over the competition that doesn't have that knowledge. Another thing you can take out of the beta and into the release is social contacts. I met my current guild in the EQ2 beta, then played WoW with them, and am looking forward to play WAR with them as well. Learning how the game works and hooking up with people takes more time than just deciding whether you like the game, so if that is the motivation to play the beta, people stay somewhat longer. But with some betas lasting several months, even those goals can be achieved long before the beta ends.
So with many player's motivation to play a beta running out long before the end of the beta, it isn't surprising to see low beta server populations after a while. It would be wrong to conclude from that automatically that the game in question will not be successful. There are good reasons to *not* play the beta if you plan to buy the release version anyway. Nevertheless I have the impression that developers are sometimes too content. We shouldn't forget that not liking the game is *also* a reason why somebody could quit the beta early. And not every beta has good feedback features installed, enabling the beta testers to tell the devs what exactly they didn't like in the game. Was it something specific to the beta, or are some features of the game just not fun? Sometimes I can't help but think that the devs prefer not to inquire about the opinions of their beta testers too deeply. Kudos to Mythic for having repeatedly changed or delayed WAR based on beta tester feedback, not every game company listens that closely to what their testers say. And while the delays might be annoying, in the end the game gets better through that process of listening. The ability to influence game design can also be a powerful motivator to participate in a beta, but it is too rarely on offer.