can't get iis7 to gzip font-face font files

By default IIS doesn't include those MIME Types in the httpCompression module. You need to modify your applicationHost.config file in: C:\Windows\System32\inetsrv\config.

This file will affect all your websites and must be opened with a 64-bit text editor in a 64-bit Windows. (Notepad2 64-bit, Notepad, do not use Notepad++)

<httpCompression directory="%SystemDrive%\inetpub\temp\IIS Temporary Compressed Files">
    <scheme name="gzip" dll="%Windir%\system32\inetsrv\gzip.dll" />
        <staticTypes>
            <add mimeType="text/*" enabled="true" />
            <add mimeType="message/*" enabled="true" />
            <add mimeType="application/x-javascript" enabled="true" />
            <add mimeType="application/atom+xml" enabled="true" />
            <add mimeType="application/xaml+xml" enabled="true" />
            <add mimeType="*/*" enabled="false" />

            <!-- HERE -->
            <add mimeType="image/svg+xml" enabled="true" />
            <add mimeType="application/font-woff" enabled="true" />
            <add mimeType="application/x-font-ttf" enabled="true" />
            <add mimeType="application/octet-stream" enabled="true" />
            <!-- HERE -->

        </staticTypes>
        <dynamicTypes>
            <add mimeType="text/*" enabled="true" />
            <add mimeType="message/*" enabled="true" />
            <add mimeType="application/x-javascript" enabled="true" />
            <add mimeType="*/*" enabled="false" />

            <!-- HERE -->
            <add mimeType="image/svg+xml" enabled="true" />
            <add mimeType="application/font-woff" enabled="true" />
            <add mimeType="application/x-font-ttf" enabled="true" />
            <add mimeType="application/octet-stream" enabled="true" />
            <!-- HERE -->

        </dynamicTypes>
</httpCompression>

These are my personal settings to compress SVG, WOFF, EOT and TTF files.

Then simply type iisreset in your command line to reload the config in IIS, or restart your computer.

UPDATE

Woff and Woff2 files are already compressed, so you don't need to do this. In fact, the client will lose performance if you gzip those.

The important thing to note is that modifying your applicationHost.config (in %windir%\system32\inetsrv\config) from the following setting:

<section name="httpCompression" allowDefinition="AppHostOnly" overrideModeDefault="Deny" />

to:

<section name="httpCompression" overrideModeDefault="Allow" />

will enable configuration of the httpCompression tag under the system.webServer tag in your web.config.

The problem is that by default IIS doesn't include the mime types for the web fonts in the list of mime types that can be compressed. Javascript and css files are included which is why you are seeing them getting compressed.

Your httpCompression settings are probably not being used, those are locked by default and cannot be set in the web.config. Take a look at this page: http://support.microsoft.com/kb/969062. In the "More Information" section it says, "you can set MIME types for the web server level only."

The only way I could get this to work on my local server was to add the mime types in the httpCompression section of applicationHost.config (this requires admin access). Setting them in web.config had no affect.