Ask HN: Service like compete.com that tracks total browser requests?

With lots of mashups and facebook apps these days, looking at compete.com or alexa doesn't really give a complete picture of the traffic that an app serves. For example, take the blog comment drop-ins like disqus and intensedebate. No one goes to their .com sites, but they get tons of traffic.

Still, in most cases of these services, there is at least 1 client request back to the SaaS domain, and this could be used to gauge the level of traffic.

Anyone know of anything like this?