I followed the demo.html and copied over all the fonts correctly and ensured that they're being added and compiled in the asset pipeline just like the rest of my fonts. However the .eot, .woff, .svg, and .ttf files aren't being found when I try to use them on the page.
There's a know issue with the sprockets server stripping out anything that looks like a fingerprint before the asset is resolved. So because the font names from Fonts.com are uuids, they don't work correctly.
More info here: https://github.com/rails/rails/issues/9788
The simplest way to fix this is to rename all the font files replacing every instance of '-' with '_' and then updating the @font-face declarations to match the new file names.