What is a "growth hacker"?

Okay, I admit it: I'm confused.  I kept up to date with "experts", "gurus", "rock stars" and "ninjas", but I've reached the limit of my understanding. Why are we (as the online analytics community) now using the term 'hacker'?  When modems were dial-up, and going online meant connecting your computer to your telephone headset, hackers were bad people who illegally broke into (or 'hacked') networks

Nowadays, though, hackers are everywhere, and one of the main culprits (especially online) are the "growth hackers".  I'm just going to borrow from Wikipedia to set some context for what these new hackers actually are:

• Hacker (term), is a term used in computing that can describe several types of persons
  • Hacker (computer security) someone who seeks and exploits weaknesses in a computer system or computer network
  • Hacker (hobbyist), who makes innovative customizations or combinations of retail electronic and computer equipment
  • Hacker (programmer subculture), who combines excellence, playfulness, cleverness and exploration in performed activities

Hacker image credit: Pinsoft Studios
So we have, "excellence, playfulness, cleverness and exploration" in performed activities?  Really?  That's what a hacker is nowadays?  Can't we just be good at what we do?  We have to be playful and creative while we're at it?  Perhaps I'm an optimisation hacker and I never realised.

My research into growth hacking indicates that the term was first coined in 2010 by Sean Ellis.  Why he chose 'hacking', I'm not sure (especially given its previous connotations), but here's how he described growth hacking:

"A growth hacker is a person whose true north is growth.  Everything they do is scrutinized by its potential impact on scalable growth. ... I’ve met great growth hackers with engineering backgrounds and others with sales backgrounds; the common characteristic seems to be an ability to take responsibility for growth and an entrepreneurial drive.  The right growth hacker will have a burning desire to connect your target market with your must have solution ...  The problem is that not all people are cut out to be growth hackers."

So:  a growth hacker is a marketer whose key performance indicator is growth.  So why 'hacker'?  Perhaps it's about cracking the code for growth and finding a short cut to success?  Perhaps it's about carving a way through a jungle filled with bad ideas for growth, with an instinctive true north and a sharp blade to cut through all the erroneous ideas?

Image credit: Recode.net

It's an imaginitive either way.  And now, five years after Mr Ellis's post, it seems we have growth hackers everywhere (ironic, considering the URL for the original blog post is /where-are-all-the-growth-hackers/  - they now have multiple websites and Twitter accounts ;-)

So - my curiousity has been satisfied: a [good] growth hacker is a marketer who will help rapidly accelerate growth for a small or start-up company by rapidly analysing what's working for its audience and focusing on those strategies with agility and velocity.  Why are they so popular now?  Because - I'm guessing - after the global financial issues of 2008-2009, there is now much more interest and emphasis in start-ups and the entrepreneurial spirit - and every start-up needs a growth hacker to crack the code to accelerated growth rates.