By using this recipe on Internet mash-up site IFTTT, you can now tweet automatically EVERY month on the 3rd by signing up just ONCE.
Mad props to Giorgio for discovering the idea.
The current plan is to still keep Thunderclap going each month as well, because it has some advantages of its own, but this new IFTTT method is a great way to maintain those casual supporters who might otherwise participate once or twice before drifting away.
And just like Thunderclap, there's a widget to embed on websites. You can find snippets of HTML to copy-and-paste here.