Twitter is a popular Social Media channel that can used for free to build a following and also offers the opportunity to pay for sponsored posts.
In a similar way to Facebook, you can also build a fan/business account on Twitter and organically grow a follower-base by tweeting relevant content or stories relating to your target audience. When you have an engaged and large enough following, you can embed posts
You can also get involved in Twitter conversations using hashtags. You can find out more about taking advantage of Twitter here.
Twitter as a traffic source can be free but if you wish to take out paid advertising on Twitter with ‘Sponsored Tweets’, there will be costs involved.