Can someone please help me to know that how can creation of too many twitter accounts help a website or earn something...
It is called "spam". It actually works but there is a lot of hassle with it. I don't recommend doing any such thing unless you don't care about your website's reputation.
Answer on your question is: NO, it won't help at all. People will notice multiple account and see that you are spamming arround on Twitter. Try avoiding multiple accounts, and stick with one.
better not, unless you have more individual sites (2 or more companies) and you kind of cross-promote them.