Why would you recommend donating 25 cents?
If you want this experiment to work, you better hope the total donations they receive is *BIG*.
That means everyone needs to donate $25.00. Not 25 cents.
If 400 people donate 25 cents and their grand total is $100, they'll consider bitcoin a total joke, with a bunch of poor teenagers promoting it.
If 400 people donate 25 dollars and their grand total is $10,000 .... they'll announce that from a mountaintop and Bitcoin will get yet another boost in legitimacy.
A lot of people can afford $0.25 (the minimum option given) but not $5.00 or more. If this hits the press, they will likely report
the total number of donations so even making a small donations is helpful. People need to know they are contributing with a $0.25 donation--that's sort of the point of micro-payments.
And people who
want to to donate more will, regardless of what I suggest. I know I did.
EDIT: I've added $0.25 (
or more!!) to the OP.