Atlassian Marketplace Licensing
The Multi Excerpt plugin now uses Atlassian Marketplace Licensing. What this means is that all payments, licensing and renewals are handled by the Atlassian Marketplace.
If you're using Confluence 4.x, 5.x+ then licensing is handled through the Atlassian Marketplace.
If you're on Confluence 2.x or 3.x then you're probably still using version 2.0.7 of the MultExcerpt plugin. This older version of the plugin still uses my legacy licensing systems.
Customer Questions:
What if I bought the plugin through the older system and I'm now upgrading to Confluence 4.?
On July 12th, 2012 I converted 92% of existing license holders. Licenses were converted and new Atlassian Marketplace licenses for those customers were made available on their accounts at http://my.atlassian.com
In a few cases I didn't have email addresses to create the new licenses. However in all cases I sent an email to the purchaser of the license.
I originally extended all licenses as far as I was able through Sept 2012 regardless of purchase date. However at this point unless you bought your original license within the last 12 months the original extension has expired. Sorry about that. I'm bound by the terms of the Atlassian Marketplace an cannot extend licenses further.
The good news is that this plugin is relatively cheap (possibly the cheapest plugin) 
What if I bought the plugin through the Atlassian Marketplace but I'm using version 2.0.7 of the plugin on Confluence 3.x or Confluence 2.x?
In that case just let me know who or when the license was purchased or the SEN of the license and I will send you a code that works with version 2.0.7.
What if we have a community or open source license from Atlassian, can we use the plugin for free?
Yes! The details and a link to get your license can be found on the Atlassian Marketplace Licensing page