Evan William, the CEO of Odeo (a Pluggd competitor), recently blogged about how pageviews are an obsolete metrics. The post mentions web site hits as a previous metric that eventually become obsolete. The post is very similar to my post from a few months back, Alexa is Web 2.0 entery #1, where I mention the negative consequences facing innovative start-ups due to the use of Alexa by potential partners, investors, the press, etc.
Evan probably cares about this for the same reasons I do. Odeo's site, like ours, enables users to listen to podcasts from a web page using a flash player. So a user can actually spend a considerable amount of time, perhaps hours, on our respective sites without generating much in the way of pages views. By any measure, a user who spends this much time on a site is a very engaged and valuable user. Unfortunately, the lack of 'pageviews' creates the false impression that the site lacks user engagement.
The user of Ajax has become very popular because it enables web developers to create richer user experience for their users. However, Ajax typically reduces 'page views' because the user stays on a single page while multiple asynchronous calls execute. Here is another case where a site may have engaged, happy, and valuable users, but the site will ultimately be penalized by the press, investors, partners, advertisers, etc., because they created a better user experience.
The final insult involves RSS and widgets. Where users can incorporate content from a web service without actually visiting the site to generate page views. With the profilleration of feeds and these widgets, this again penalizes innovative start-ups. Actually, I think the notion of a portal is also becoming obsolete because of widgets and RSS. In fact, I don't think of Pluggd as a portal. I think of Pluggd as a Nexus that brings things together, both aggregating, and syndicating content and functionality.
Since Alexa uses a browser toolbar installed on the client, it could easily be modified to monitor HTTP traffic to account Ajax traffic. Also, the Alexa client could track the time spent on a site to account for scenarios like listening to audio or watching video. Another option, would be for companies like Hitwise that partner with ISPs to measure traffic to add relevant metrics that are more appropriate for this next generation of web service.