Since you talk about a flattr like system all the time:
I run an online magazine with hundreds of visitors everyday (we're not at
1000 yet but still) and i also tried to make some money with a paypal
donation button. The proposed amount of money was tiny: 50 cents or so;
yet, we never received a single donation.
People are really content with our articles, yet they maybe think "somebody
else will pay" or "until now it worked for free, so why not in the future".
I can't see why this should be any different for other projects using
donation systems.
