This is such a cool way to get donations. Like here, this is free, we would appreciate a donation but we'll only ask twice and if you still can't afford to donate you can use it anyway and you will be permanently activated at that point. Well with an invite like that, unless if I was a kid getting a dollar per week allowance, there is no way I could pass by a chance to help if doing so was at all within my range of possible. (And if you use PayPal you don't have any excuse at all.)
And, oh yeah, I only donated a tad over 20 and mouser was so appreciative. I was really tickled because it seemed like so little for such a great program, but it was all i could afford that that particular moment; but mouser was appreciative anyway and i didn't feel like such a miser anymore.