You can now add Raptr to your site/forum profiles.

Another website I've never heard of. I wonder if there's any methodology to how sites like this come into existence and which grow popular, or if it's just totally random...

I'll bet its like Cubivore.

You would have a much better chance of knowing what Raptr is if you were a frequent gamer on Xbox 360 or Playstation 3, as you can plug your online presence on those consoles into Raptr and have it track how much of what games you played, giving you a pretty neat rundown of how you spend your time gaming, cross platform. 

Isn't this basically the same thing that the Nintendo Channel offers. You can track what games you have played and how long of a peticular game.

Yes. Raptr will keep track of all those hours. They even have a PC application to track PC games. The program also has a cross-platform buddy list and instant messaging. It's not perfect. Double clicking a Steam buddy will just launch the chat window in Steam. It not too much of a issue, though.

In my experience, the stats gathered in the Nintendo Channel are not particularly accurate.

QFT

It's a good approximation, but I've seen it not go up at all after putting several more hours into a game.

If you checked it right away then the new playtime might not be counted yet. Sometimes it takes a day or two to show up. Also, if you ever play a game when the Wii is not set to the correct date and time, it will very likely not count that playtime in the total.

The Wii's internal tracker is buggy as heck. I've had games suddenly register 23:59 for no reason.

Really? That's interesting. I wonder what caused it? I haven't seen any issues like that which I recall, the only thing I noticed is that if the Wii is unplugged or the power goes out, the time will show up as only 1 minute. Which isn't even really a bug, probably just how the system works.