Just judging from the table it seems like your usage would have to be pretty excessive to get charged. 25,000 map loads per day == someone loading an embedded map on your site every 3.4 seconds. The site also says they aren't going to stop your maps loading or display a warning automatically or if it's a one-day thing (i.e. your site gets slashdotted) but only if it's continuously excessive. Very few folks need to worry about this and those who are getting 25,000+ hits per day on an embedded map alone can probably afford the $4 per 1,000 additional loads. I just don't see too many folks this will actually hurt, and I can't imagine it costs Google $0 for your 25,000 loads per day they're giving you for free either.