I was with AOL for 5 years and recently the Product Development Director for a startup in Reston, VA. We had a rule of thumb at AOL when developing any products (if anyone's interested)...
If you can build 10 features for people, never build more than 5 of them per upgrade.
The bottom line is, people adjust to whatever 5 things you give them and everything else is gravy. If you're building the software for developers/techies, it's an arguable and different matter. If you're building the software for the average internet person, choose 5. That's my 2 cents.
Rebecca
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