I use Single Website license of lightbox slideshow jquery. Is it possible to upgrade it to Unlimited Websites?

Q: I purchased the VisualLightBox single license a couple months ago but would like to upgrade to the business license for multiple sites. Is there a way I can just pay the difference and get the upgrade?

A: Yes, you can upgrade your license for a price difference.
Price will be $20:
$69 - $49 = $20.00
$69 - is a price of VisualLightBox Unlimited Websites License;
$49 - is a price of VisualLightBox Single Website License.
Please contact with Customer Support at support [at] visuallightbox [dot] com for further instructions.