Social media sites can also be a powerful tool is used well. You can drive a lot of traffic from your twitter or facebook account. I have been using them for a while and they are great.
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I know Youtube is the great source for driving traffic. But it is not easy to get youtube video at top. And you can not get views and traffic untill your video is at top position for used keywords.I agree Youtube is a great source of traffic. Aside from this, any social media is great for getting attention for any one feature or article you may have and it often brings in repeat audiences if your article is really good enough to convince them of the quality of your site or blog. One post on a popular social media site can bring in tens of thousands of viewers if you share the right topic at the right places.