IIS 7.5 gzip compression at shared hosting

I have a web-site, which uses ASP.NET and is hosted at IIS 7.5 shared hosting, so I have no direct access to IIS settings. Now I want to enable gzip compression of my pages and css/js files using IIS capabilities, but none of recipes found at the Internet worked for me. For example, when I add what is written here to my Web.config, nothing changes: no errors, no compression.