The single skill that you need to develop is the ability to drive traffic. How you choose to do that will depend on your market. There are so many different ways using both paid and free methods but you should find one or two ways that you are happy with and concentrate on them until you are an expert at them. Don't try everything you read or you will never become a master at any one of them. There are people using social media, press releases, you tube, even article marketing still has it's adherents.
Personally I would go for paid methods if you can afford it, but every method has a learning curve. Concentrate on two only.
Once you have found a couple of ways that suit you, then to build a business you need to build a responsive list. That again has a learning curve, but if you follow good marketers, analyse their email campaigns and build your own swipe file.
To be honest you can learn more from the top marketers by following and analysing what they are doing than you ever will from buying products that they are promoting.
If you notice the big names are concentrating more and more on retargeting as opposed to list building. You know the free download with no optin required then the ads seem to follow you round the web.
If the big boys are throwing money at it, that suggests that they are getting a good ROI (Return On Investment). Certainly that is one of the top items on my Must Investigate list!
