Twitter is more popular than Google Plus.

The question should be "which is the best social site for my business?"

Answering this question will make it easier to decide what social network is the best.

If you want to work on your website seo and make it go higher then Google+ is better, it's a Google product and you want to rank higher on Google search engine, which is a Google product as well :D

If you want to get more users to your website (traffic) then it's better to use Twitter, but to be honest Facebook is the best one for this purpose in fact.

What if you want to get traffic to an online store (it can be just a profile on a website like Sunforg T-Shirts for example) then it's Instagram without a doubt.

Women related niches (food, make-up, weight loss...)? Well this time I need to say it's Pinterest for sure.

For professional purposes? LinkedIn is the master.

However I see that using a combination of these social networks is the best way, for example increasing Social Media Presence for a website using Google+, Facebook and Twitter will produce better results on both ranking and getting traffic.

Twitter is the best

I think Facebook is best for marketing and promotion,