Microsoft points annoy me the most - I'd rather just buy the individual item at the price it is and not buy incriments of points, and I'd rather it just be in cash rather than having to convert it into a pseudo-currency in your head to figure how much you are spending (ish).
Rich
Unfortunately, that's the exact reason they do it. Well... that and ensuring you always have a few spare points which encourages you to buy the smaller crap.