Up until now having a Google Plus account was a mandatory requirement for having a Gmail account but now that is a thing of the past. When you try to sign up for a new Gmail account, a Google Plus account is no longer mandatory.
A Google spokesperson confirmed this:
We updated the signup experience in early September. Users can now create a public profile during signup, or later, if and when they share public content for the first time (like a restaurant review, YouTube video or Google+ post).
You would however be required to create a Google a Google Plus account if you want to comment on a YouTube video or use a social feature of any of Google’s services.
This move comes after the company was criticized for breach of privacy of its users and annoyance in having a Google Plus account.
People are hoping that Google will demarcate its services while at the same time integrating them well with each other. This moves goes a long way in solving that. read more at http://www.androcid.com/