I had written up a long, comprehensive and timely set of thoughts about what went wrong with Google Wave, but WordPress ate it so you’ll have to take my word that it was awesome and instead put up with this rather late and significantly shorter thought.

There are lots of opinions around about why Wave failed, and they show that it was a combination of a lot of factors from poor UI, inexplicable purpose, unreliability and simply combining too many technologies that didn’t always fit (e.g. people don’t always want what they type to be shared immediately but real time collaboration was forced on them). Certainly I experienced most of those downsides, but the thing that really drove me crazy about Wave was it’s primitive support for notifications.

The people I was trying to follow on Wave were mostly on the other side of the world, so most of the time I wasn’t collaborating with them in real time, I was trying to come along afterward and keep up with the changes. Initially that meant logging into Wave and trawling through every wave to see if anything was new and later email notification widgets came in then built-in email notifications. Even with the email notifications though, it would tell me that something changed, but it was way too difficult to find out what changed. I’d have to log back into Wave and try to rewind and replay the activity in the wave, which meant living through all the intermittent changes and most of the time it just didn’t work at all.

What I really needed was a clearly highlighted diff included right in the email notification (or via RSS/Atom). I didn’t care how many different individual edits had been made, I just wanted to know what was different between the last time I saw the wave and now.

It’s not the first service I’ve seen suffer from the lack of notification problem – it’s a surprisingly common oversight, but it’s crucially important to success. If you lack good notifications you’re depending on the user seeing enough value on their very first visit to start coming back regularly so they see the changes and keep interacting with the system. With good notifications, users have a much better chance of seeing the value proposition because the system keeps reaching out to them with useful, valuable information. Just sending lots of email doesn’t work – that diminishes the value, it has to really give them an idea of what’s been changing.

The two best examples I’ve seen of this are Dopplr which has a million different ways to continuously view what’s going on without actually going to the site and Facebook which sends very effective email notifications, although the default settings are overly noisy for my tastes they have good controls to limit it to precisely what is useful. Twitter is also very good.

Advertising driven sites may make their money by increasing page views, but ultimately allowing users to keep up with what’s happening without coming to the site itself is a far more effective way to get them hooked on the service and keep them using it.