title: IIS Compression vs manual GZIP
body: <p>I'm currently working on a project that passes some geo data through a WCF service. This data gets up in size (2-4mb sometimes, and in special cases even more). To help decrease the size of data over the wire we've initially enabled gzip compression on IIS (this worked wonders). Alas in testing we found one of the proxies we use makes this worthless.</p>
  
  <p>So, instead I've decided to compress the data itself before it's sent out of our service. I'm using SharpZipLib in both WCF and our Silverlight client. It works well and shrinks our data from about 2.9MB to about 400KB, however the IIS compression was able to bring things down even further. </p>
  
  <p>Now I'm curious...</p>
  
  <ol>
  <li><p>Is there any secret sauce behind the IIS GZip compression that makes it compress better?</p></li>
  <li><p>Is there a better compression algorithm that could be used?</p></li>
  </ol>