Why do we feel entitled to free app updates?

Julen Verea, at AppFreak, expands on the discussion surrounding the value of apps with comments from MacStories' Federico Viticci and Graham Spencer, as well as other tech fans (including yours truly).

The main question:

Until when is it reasonable to expect support of an app before it’s discontinued or we have to pay again?

It's not an easy one to answer and, given the broad range of answers, it's a problem without a simple solution. 

Source: AppFreak