I am using Twitter for a long time and I have observed that Twitter is really helpful for SEO as it drives traffic from Twitter to website which is mentioned in the BIO section of the Twitter account.
All social media website have own traffic. so we can't compare between them. Yes, Twitter is one of them from where you can good amount of traffic for website.
Social media sites drives good traffic to website and so is Twitter which is social media site and drives traffic for website. Same way is Facebook and google+.
Twitter has a long history with Google, leading to a lot of confusion about whether signals from Twitter influence Google’s search results. Today I’m going to sort that out (spoiler alert: it doesn’t). Then I’m going to look at current best practices for upping your influence in the search using Twitter.
All social media web website own visitors. so we can't evaluate between them. Yes, Tweets is one of them from where you can great deal of visitors for web page.
SEO counts the hashtags and back links and thus the traffic you invite. Twitter works on hashtags and thus provide you easier searchability and visibility, ranking you higher in SEO.