Why do i need to keep the extension up to date
You should always have the latest version of the extension installed because in every new version of the extension there are new functions and more important, there are bug-fixes.
Also, sometimes data providers (such as Instagram, Facebook, YouTube, etc...) change their code and some functions may become unavailable and even whole extension functionality may be broken. In that case we release the new version of the extension which is compatible with the new changes. So if you will not update the extension - it will not work.
How to check if there is a new version of the extension you can read here: How to check if there is a new version of the extension
In order to receive new version of the extension you need to have the Updates&Support period active. To extend the Updates&Support period, you need to click on "Extend updates&support period" button in your account near to the questioned extension.
More about payments in this article: Is it a one-time payment or a subscription?.