Web API JSON Dynamic Compression

applicationHost.config

        <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/javascript" enabled="true" />
                <add mimeType="application/atom+xml" enabled="true" />
                <add mimeType="application/xaml+xml" enabled="true" />
                <add mimeType="*/*" enabled="false" />
            </staticTypes>
            <dynamicTypes>
                <add mimeType="text/*" enabled="true" />
                <add mimeType="message/*" enabled="true" />
                <add mimeType="application/x-javascript" enabled="true" />
                <add mimeType="application/javascript" enabled="true" />
                <add mimeType="*/*" enabled="false" />
				<!-- compress JSON responses from Web API -->           
				<add mimeType="application/json" enabled="true" /> 
            </dynamicTypes>
        </httpCompression>