Ethan Dunham: "The hack that makes this work is the '#' following the EOT filename. Seriously."

"All of the fonts on Fontspring that are marked as '@Font-Face Ready' can be downloaded and used in your websites without recurring subscription costs. [...] Our best license allows you the designer to use the fonts in an unlimited number of domains under your control. Other fonts must be purchased by the number of domains you expect to use them on."