What benefit does bitcoin provide over using a credit card? I am brand new to Bitcoin. I am retired investor. 

What benefit would using Bitcoin have over, say, using a credit card, etc.? It appears that Bitcoin is primarily designed for businesses, buying, selling, and using Bitcoin as the exchange medium.   

I saw a chart which showed the Bitcoin/USD value at approximately $32 and then dropped to $2 and now is back around $15 as of August 18, 2012.
I don't consider these to be competitors.

Credit cards are a convenient way of doing payment processing on top of fiat currency. Bitcoin is a digital currency on itself.

Sure, Bitcoin today can function as a very rudimentary way of doing payments (just like cash-via-mail can be), but it's not particularly good at it - all it provides is storing and transferring value. What I hope is that in the future it will become a platform upon which payment processors can build. Since the currency is already inherently digital, building a payment platform on top of it should be significantly easier. Furthermore, since it is decentralized, everyone has the ability to become their own payment processor (or bank...).