The buy button redirects to a webpage.
It is there in case you want to know the URL when you buy the application for another computer or somebody else wants to buy it.
I write in About:
Multiple Search and Replace V4.0 – 4dots Software
Developed by Alexander Triantafyllou
Copyright © 2016-2017 – 4dots Software
Business Version – Licensed
License Key : BUS*-****-****-**40
Product Webpage :www.4dots-software.com/multiple-search-replace/
Buy now !
If there is a key, then why does it offer: Buy now?! (The program is registered)