Every month, the marketing blogosphere redefines a slew of concepts and strategies on everything from analytics to customer experience. For concepts like content marketing and lead generation, the measurements of success are constantly evolving, but the basic definitions really haven't changed. Lead generation is about generating leads. Content marketing is about using content within your marketing campaign. They may be new concepts to some of us, but at a high level they mean what they are.
Conversely, one concept that isn't so well defined is disruptive marketing. At its worst, a disruptive advertisement or marketing message is intrusive with little to no accompanying value. This was a big problem 10 years ago, when the Web was littered with intermittent pop-up ads and aggressive email marketing was rampant.