You can't abolish the nickel without getting rid of the dime too. That's because the lowest-common denominator of the quarter (25c) and the dime (10c) is the nickel (5c).

To see how search varies depending on where you are: https://adwords.google.com/select/AdTargetingPreviewTool

One can also stop the flow of pre-approved credit cards with an opt-out system similar do the do-not-call list.

It worked very well for me.

http://www.ftc.gov/bcp/conline/pubs/credit/prescre en.shtm