I love the idea of ringing a bell for a sale (when you getting higher rates you could ping less often with a different pitch). I think sounds are a great side channel for event notifications.
IIRC, in one of Wil Shipley's presentations, I think he mentioned that they did this at Omni, and while the constant ringing of cash-register sound effects was nice at first, it got old fast.
I certainly agree, and I think this applies to more than just businesses. Blogs, for example, greatly benefit from live stats. Which is why it's so annoying that Google Analytics doesn't offer live stats.
Being able to quickly spot where the traffic to an article is coming from allows you react to it, and maybe go to that traffic source and help shape the discussion there. When submitting articles to multiple sites, it also gives you a better idea of how your article is performing. Sometimes, this has allowed me to tweak an article after posting it, to fix perceived errors that were hurting it in some way.
And of course, this applies even more when you're looking at a business.
