How to make sure that users see the new logo?

Question

We have canceled the logo for our website, and I want users to see the new image when they come to our page. A logo is a background image for a div. How can I make sure css is updated when users come to the page?

Answer 1

Change CSS URL to ie style.css?newVersion=1.

Answer 2

Add an unused querystring parameter (for example, ?version=2011-06-01) to create a new, non-signed URL.

Answer 3

(ime) - css:

.div-with-logo-image-inside {
  background-image:url("data:image/gif;base64,R0lGODlhhwASAPcAAAAAABD ... ");
}