Wow, if that's true their emails are really deceptive...
"About a year ago, you donated $15 to keep Wikipedia online for hundreds of millions of readers. I'm surprised by and deeply grateful for your continued support. You are part of the 2% of readers who donated to support Wikipedia. We need your help again this year ... most people will ignore this message. We have no choice but to turn to you: please renew your gift to ensure that Wikipedia remains independent, ad-free, and thriving another year."
I read that as "please donate or we might have to use ads to keep lights on if you don't"