How are vendors successfully selling apps with features that are already builtin into Jira?

[Pankaj Jangid]

Let me state this already that we also do this. Jira has a feature to create requirements and manage them under Jira itself. We also sell this. But how are vendors successful in selling the same thing as 3rd party solution? I am not saying that this should not happen. It is benefiting most of us.

But I want to know what triggers a buyer to purchase such a solution? Is it the

1. Set of features
2. Customer support
3. Existing relationship with the vendor

Or any other reason that you might think is the answer to this puzzle.