They're stating their mission and then asking for donations. At least that's how I see it. There is no endeavor that is guaranteed to succeed. Money isn't the only problem they are facing.

I personally greatly prefer that statement to something like "if the money runs out, we'll have to close IA. Please donate." which somehow sounds like blackmailing. EDIT: The former doesn't feel like marketing to me, might lead more people to donate and I would expect most of us (like you and me) to understand that they do not make any promises, except doing their best.