eCardMax is a script I have thought about purchasing a few times though I have been reluctant to buy it because I don't think I have the time or money to make it a success. You can see the script in action here.
Essentially the script lets you build one of those flash e-card stores where people can send flash animations to their friends via email to celebrate their birthday, anniversary, special occasions etc. The script has a lot of features :
Registered users can send voice messages with e-cards; create an album to upload photos, poems and music files; set up advanced address book; receive birthday reminder alerts; stay organized with card history and calendar; and much more. Admin can add watermark logo to protect ecard photo on the fly.
It does look like a good script but as I said before, I'm not sure how you could make good money with a script with this long term. I'm sure if you got enough backlinks to your site it would prove popular and you could sell text links or banner impressions but again, this can be said of any site. If you're looking for a new type of site to develop, it's worth checking out.
Link : eCardMax