What is exactly a trend?

What is exactly a trend?

(Source Trendwatching.com)
How about: “A statistically significant change in performance of measured data which is unlikely to be due to a random variation in the process.” That won't get the creative juices going. So consider the following definition, which we came up with years ago and which still holds pretty well:
A manifestation of something that has unlocked or newly serviced an existing (and hardly ever changing) consumer need,* desire, want, or value.
At the core of this statement is the assumption that human beings, and thus consumers, don't change that much. Their deep needs remain the same, yet can be unlocked or newly serviced. The 'unlockers' can be anything from changes in societal norms and values, to a breakthrough in technology, to a rise in prosperity.
Example? One of the core human needs is to be in control, or at least to have the illusion of being in control. No wonder then, that the online world is so addictive. After all, it firmly puts the individual in the driver's seat.
Just give it a try: apply the above definition to your daily spottings and observations of how consumers behave, and how that behaviour is forever changing, and you will find that many seemingly unconnected business success stories will start to make sense. Successful innovations often satisfy existing, dormant needs in new and attractive ways.

Rereading Maslow's Hierarchy of Needs never hurts.