This year if you wanted to advertise during the Super Bowl, you had to pay CBS almost $3 Million dollars for 30 seconds worth of time. That's a lot of money for only 30 seconds - but you do get to advertise to almost 100 million viewers. However, with only 30 seconds, you better have a great elevator pitch!
To me the answer is easy - it is worth the cost, if you get it right. If you have a great message and have it presented in a way that people are going to either a) Talk about it constantly the next week or b) Have it replayed on YouTube on different 'best of' lists - then it is money well spent
However, what you can learn from Super Bowl ads when it comes to communication is important. What made those ads memorable: Were they funny? Did they have great visuals? Was it a great story? Usually they combine a combination of those elements added with some name recognition.
For example, the Career Builder commercials. This website has had some of the most memorable commercials over the past few years - they are funny while relating to a good majority of their viewers. A lot of viewers are stuck in jobs they don't like and have to deal with a lot of things they wish they didn't. It has great humor in it because it puts people in a 'typical' setting, but in a funny surrounding. This year was no different.
What we can learn in public speaking from those commercials is this: know your audience and try to adapt to them, while remaining true to yourself. If you can be funny - be funny. If you are not - don't even try. Keep true to yourself and your brand if you are representing a company (especially your own). If you can adapt to your audience a little and try to appeal to them, then your 'commercials' will be a success and will be money well spent.