Advertising Age has recently spent quite a bit of time dissecting the Jay Leno effect on NBC and viewership, ratings and advertising. For instance, “A 30-second spot in “Jay Leno” costs between an average of $48,803 (Friday nights) and $65,678 (Tuesday nights)… In contrast, NBC was able to secure ad prices of between $78,000 (for “Lipstick Jungle”) and $146,679 for programs that aired in its 10 p.m. slot Monday through Friday in the 2008-2009 programming season.”

Those stats alone do not tell an entire story, but it is bad enough that Ad Age put together a top ten list titled: “Top 10 Lessons to Learn From NBC’s Failing Leno Strategy: How a Network Shot Itself in the Foot by Cynically Cost-Cutting — and Betraying Its Viewers and Affiliates“.

While Ad Age’s list is aimed at media companies and personalities – it is, for the most part, applicable to all brands, companies and entrepreneurs. So whether or not you find Jay Leno funny – and whether or not NBC finds success with The Jay Leno Show – these lessons are relevant:

10. In a morphing media marketplace, track record means nothing.
9. Longevity is not the same as brand loyalty.

8. Cutting back on quality, even in a recession, can be brand suicide.
7. It’s dangerous to pretend your brand is something it’s not.
6. Timing affects perception.
5. Time-shifting aside, the basic rhythms of broadcasting may have an almost biological basis.
4. If you’re in media, you’re in a way different business than you were even just five years ago.
3. If you’re going to suddenly and radically change a large proportion of your product line-up (like, say, 33.3% of your weekday prime-time schedule), there’s — surprise! — going to be a ripple effect on your overall brand.
2. Allowing one outsize personality to hijack your brand identity is generally not a good idea.
1. Jay Leno is a helluva lot more annoying when you’re still wide awake.

Read Ad Age for the entire list with commentary about each bullet.