The online marketing landscape in 2015 will look very different than it did even three or four years ago. Mobile marketing, social media and content marketing will likely continue to be some of the most important elements of a marketing campaign. A term like "email marketing," however, already sounds like an outdated technique.
Of course, experienced online marketers know that this definitely isn't the case. As marketing approaches become stretched across many different platforms and tons of content continues to be produced, email marketing will remain one of the most powerful strategies.