Web App Complexity Metrics / Scoping a Web App

Since we're on the topic of metrics, I'd like to throw out this question:

How are you currently scoping web applications for review?

I'm trying to come up with a better way to measure the complexity of applications (and thus, the time required to test). I'd like to keep it as simple as possible.

Here's what I've got so far:
- How many backend components are involved? (Database / Middle Tier)
- Does the application have a web services interface?
- Are client-side - javascript - flash - or other RIA technologies used for business logic?
- How many static pages?
- How many dynamic pages?

What other metrics are you using to scope application assessments?