Newbie here with a question about 'value' of points...

I was checking out the AA website and found flight US/Europe that yield an extra 4000 AAdvantage Bonus points but under T/C it says:

"Bonus miles do not count toward elite status qualification. Registration prior to travel is required."

So what good are they?? And while I'm at it - do the points accrued from cc purchases have a different 'value' than points accrued when one actually flies to earn them?

Thanks for the clarification!
DD