It's part of a larger tweet-a-thon and awareness raising effort. The 3rd of month has long been the Shenmue 3 thunderclap. Everyone is encouraged to at least tweet #SaveShenmue & #30onthe3rd that day in unison, and there's an autotweet site set up for it:
http://teamyu.net/Shenmue.III?action=autotweetAs for upping pledges, maybe everyone's already tapped out, maybe they're not. But if there's any chance at all, even a slim one, that even half of the current backers can increase their pledges by $30 that day, that gives us an additional 690,000 roughly. That puts us over the crucial 4 million dollar limit, hopefully generating buzz because it means we doubled the initial goal.
Maybe it will whiff and do nothing. But there's a chance. To that end, I'm upping from the 175 level to the 250 collector's edition that day, and also donating 60 to my friend so he can back. That's my absolute limit at least for now. But the final surge we all hope comes generally tends to be from fence sitters, not people who've already backed, so I don't think the two will conflict.
In my completely non-empirical, gut based opinion... it's our best chance of having two big surges before this is over instead of just one at the end. And that's worth trying for me.