For those who didn't see it in their Contact Sheet mail:

We recently announced some changes to how our Extended License options are structured and priced. We streamlined and simplified the system, introducing a fixed, flat-rate scale that's easy to use for our buyers. For you, our contributors, that means more royalties from Extended License sales. If you haven't opted in to the EL program, you can do so under the Contributor section of your iStock Control Panel.

http://www.istockphoto.com/license_purchaser.php

Regards,
Adelaide