A Web site should be both elastic and grounded.
Web Elasticity: Open to change. Receptive to users. Connected to users. Embrace trends, new applications, new thoughts.
Grounded: History. Set of visitors/followers. SEO basics base. Copy depth and width. Real links. Technical grounds (competent server, etc.).
It's tough to fake being grounded--as it should be. Being grounded takes effort, maintenance and know-how.
It may be easier to embrace elasticity; however, doing it right takes heavy maintenance, testing and awareness.
#1: Web elasticity must be genuine.
Let's say you want to "appear connected" to your audience, so you throw a Twitter app on your site and forget about it. You may know that's a non-elastic move, but surprisingly it's still happening. Some folks (and rooted corporations) still don't get it.
I think one of the greatest things about social media is that you can't try to "appear connected" to your audience any longer. You either are or you aren't--and that's what is apparent.
What "grounded" Web sites/corporations do you think are doing well with balancing their roots while maintaining true elasticity?