The easier it is to find and repurpose approved content (especially when it’s highly technical) for distribution to multiple digital channels, the better you can meet customer needs and stick to a single core message in every language. SCIEX is an example of a company that simplified, collaborated on and repurposed content, standing out as a rock star by creating a highly successful integrated digital marketing solution.
Considering that most marketing involves some form of published media, it is almost (though not entirely) redundant to call 'content marketing' anything other than simply 'marketing'. There are, of course, other forms of marketing (in-person marketing, telephone-based marketing, word of mouth marketing, etc.) where the label is more useful for identifying the type of marketing. However, even these are usually merely presenting content that they are marketing as information in a way that is different from traditional print, radio, TV, film, email, or web media.
Going into network marketing? Understand that if you're not close to the top of the food chain there, your ability to generate any serious amount of income will be limited. Be wary of the hype and the sales pitches that get you thinking that it's going to work the other way. Simply understand that you're going to have to work hard no matter what you pick to do. Email marketing? Sure. You can do that. But you'll need a massive and very targeted list to make any dent.