You can reimplement the features of other business/webpage if it's clear that it is a different page. (Just don't sneak in the server room at night to steal the source code. :) )
It's like Coca Cola and Pepsi. Just keep the look and feel / label different to avoid confusions. If you want an example in software, think about MS Office vs Open/Libre Office.
It's like Coca Cola and Pepsi. Just keep the look and feel / label different to avoid confusions. If you want an example in software, think about MS Office vs Open/Libre Office.