Have you seen one of those post-it pop-up? The one that looks so realistic, with awesome shadow effect. If you don`t know what I am talking about, try opening the following website:

http://myhobbybooks.com/wowpop

They look awesome don`t they?

And something like this is always good for your web marketing campaign. One reason, it never gets blocked by pop-up blockers. And another, it really grabs the attention of your web visitors.

This is good when you want to increase subscription rate to your ezine, or promote an affiliate program, or even increase sales.

But you wonder, how do they do it? You thought that you can achieve similar result, and you try, andd try, and try ... you tried GIF image, JPG image, none of those can get the job done.

But there`s one thing that you just don`t know. Many pro web programmers know this, but not the normal web designers ... maybe even most web designers don`t know how to do this.

The secret is in PNG image format.

PNG image format is the little-known image format that you can use on the web. PNG image format is unique because you can do the Alpha effect with it. The Alpha effect is where you set transparency factor on certain areas on the PNG image. That is what makes the shadow looks so real.

With the Alpha effect,, you can set transparency factor from 0% to 100%. So it can be 30% transparent, 50% or even 79%. Have a look at the pop-up again, and take a close look at the shadow - Now you know how it`s done.