There is a trend in the software industry to expose one’s core infrastructure via APIs to allow other businesses to leverage that infrastructure to build new applications.  Who is moving in this direction?  Amazon, Google and Salesforce.com all offer APIs that allow ISVs to leverage their infrastructure to develop applications on their platforms. 

ExactTarget Embedded is ExactTarget’s new product offering for developers and ISVs.  The ExactTarget Embedded web service APIs to allow ISVs to leverage our messaging and deliverability infrastructure to develop applications within or on top of their applications.  One can quickly get to market with less up front capital investment by building applications on ExactTarget’s suite of web services.  More importantly, letting ExactTarget manage the deliverability and back end process of sending email takes the burden off of development resources, freeing them up to work on other tasks.

Here is a summary of ExactTarget Embedded:
http://email.exacttarget.com/ETWeb/partners_embedded_detail.aspx

ISVs both big and small are finding value in leveraging large capital investments made by ExactTarget and other software companies.  Here are some similar examples from Amazon, Salesforce.com, and Google:

Amazon
http://www.amazon.com/gp/browse.html?node=3435361

Salesforce.com
http://www.salesforce.com/platform/

Google
http://code.google.com/more/#label=APIs&product=gdata