Those are decent (yet obvious) ideas for a startup that appeals to the sort of people who read TechCrunch. Most people have never heard of Twitter (or at least never been there) or killerstartups or squidoo. We've found out the hard way that marketing toward Joe the Plumber takes a much different set of tricks.
You're right, these are pretty obvious and appealing to a mass audience is much harder than just marketing to the tech crowd. I'd suggest checking out Andrew Chen's blog: http://andrewchenblog.com/
This guy is THE guy to read when it comes to user acquisition.
