Let’s say that you are selling dog food. And most likely you will want the best traffic possible on the keyword “dog food”. Creating/building/earning all of your links with the same anchor text will get you in trouble. If you are having 600 links from which 400 use the anchor “dog food”, you might be facing a problem; it will surely raise a red flag to the search engines. And we all know what search engines do when they are getting these kinds of alarms: they begin applying penalties and move your websites so far from reach of the user that you will not be even listed in top 100. 

Facebook ads are a great way to get highly targeted traffic to your blog (landing page, fan page, what ever). Although not a free traffic source, it is a great one. The price is not very high and I think it is pretty acceptable considering that you can choose demographics of Facebook users that will see your ad. I had great success getting traffic that converts on one of my niche sites.
Comments need special attention to be successful, though. Generally, you will have strict rules to follow. You can’t simply leave a “this was great, hey check out my site” comment. It will either be filtered for spam or it will be ignored. You need an insightful, detailed, and helpful message. You need to expand upon the topic in the post, argue against it, or support it with your own data. The point is to be valuable and attract positive attention.
Putting it simple, duplicate content is content that appears on the world wide web in more than one place. Is this such a big problem for the readers? Maybe not. But it is a very big problem for you if you are having duplicate content (internally or externally) as the search engines don’t know which version of the content is the original one and which one they should be ranking.
We used to like best to see a fairly balanced mix, back when there were mostly just three sources: Organic, Direct, and Referral. Organic Search traffic is a good sign of general site health, it’s usually the top source of conversions, and it generally shows great ROI. Direct traffic is often the people who love your site or are coming back to buy after they found you in some other way. These two groups of visitors are probably the ones that bring you the most sales or leads.
This is a crucial area. If you do not have schema markup and rel="author", you are costing your business money. It is as simple as that. As an example, say I want to make spaghetti (pasta) for dinner I search for “Spaghetti Recipe” and instantly I see some great markup in play, but one competitor has no markup and no rel="author" they are losing business in my eyes. Wouldn't you agree?.
Mobile traffic: In the Groupon experiment mentioned above, Groupon found that both browser and device matter in web analytics’ ability to track organic traffic. Although desktops using common browsers saw a smaller impact from the test (10-20 percent), mobile devices saw a 50 percent drop in direct traffic when the site was de-indexed. In short, as mobile users grow, we are likely to see direct traffic rise even more from organic search traffic.