Hello! My name is Humberto Valle, I'm a marketing strategist for www.unthink.me. The term “growth hacking” is now being widely used to describe startup marketing, but its meaning has changed since Sean Ellis originally coined the term in his 2010 blog post. You have a very good question here! In short, the answer is No, its not just for SaaS. Service based companies, professionals looking for work, and other non-digital physical product based companies use Growth Hack methodologies every day with great success.
Let's get a few things straight first, there is no traditional or digital marketing, only good marketing. Just as how there is a difference in advertising and marketing. Marketing is a management level effort for anything customer facing while advertising is much much simpler than that, albeit still a complex responsibility.
traditional is now also including platforms like social media and PPC so in many ways, growth hackers are referred to as that when they can combine management level insight in a business and it's market and pair with easily launched and measured customer acquisition tactics. Sometimes these efforts can very well combine traditional and new traditional as well as highly technical efforts.

What differentiates a growth hacker from a "traditional" marketer? Well, while a growth hacker certainly has the skills of what is now becoming traditional marketing in his toolkit, Sean Ellis recognizes that those skills are not always relevant to most early startups, but just as well they are used by many.

I have personally implemented non-technical growth hacking methodologies for service-based businesses such as in the cleaning industry, manufacturing of sports apparel, table top games, and others. I haven't had the chance yet to apply Growth Hacking to a SaaS which tells me that it can be done outside of the SaaS industry. If you think about it, growth hacking is understanding where your customers are coming from, what will make them tick, and how to be in the right place at the right time with an offer that is so easy to claim or engage with that it's almost intuitive so the conversion is high. Growth Hacking may have been coined by a technical aspect for a SaaS but in reality is no more than good practice marketing efforts at a management level effort.
As a business owner, startup founder, or high level CEO - and of course as head of marketing - you must know who your ideal target it, the market, the competitors, things that make your prospects tick, how much are they willing to go through to acquire what you offer, what are their stages of decision making, howlong is your pipeline for conversion, where and how to retarget them, etc. - this is what every good marketer should be able to do, but in many ways it was unfortunately coined for the higher level experts like us who do have this type of insight when it reality it should be common practice for anyone wanting to call her or himself a 'marketer.'

Growth Hacking... Geez a buzz phrase for everything.

What's really covered in the idea of Growth Hacking relates to the idea of using a merge of conventional + unconventional methods to rapidly increase conversions + revenues.

This approach works well with everything from supplements to podcasts then anything else you can imagine.

What you're likely really looking for...

Ideas to rapidly increase your conversions + revenues.

Suggestion... Scan Clarity + book phone calls with whoever looks interesting.

Do brainstorming sessions with random people + record your calls.

A single idea may boost your revenues into the stratosphere.

One book you might find useful...

"Free" by Chris Anderson

Pay particular attention to oddball ideas like "Sample Labs".

Also how Jello was able to entice people to use rendered cow cartilage + cow hooves as desert.

This book is full of unconventional approaches of "Monetizing Free" which can be adapted to any business.

Also, the book series...

"Marketing Mistakes and Successes" by Hartley.

Understanding failure, is a great way to initially tool for your success + then continually retool to maintain your success.

The simple answer: NOT AT ALL.

As Humberto mentioned "Growth Hacking" is just a concept of low budget and focused marketing approaches.

May I ask, in what professional service is your business located?

Depending on your industry, the first thing i would go for is social-media. In this area there are plenty of great possibilities to hack your business growth.

For example, if you are location based company, I would use the Instagram Hashtags or places to search nearby potential clients.

Or take a facebook group instead or for example a local meetup, which you can host or go to.

In my opinion, the most important thing is, that you bring first value. If you are just looking for a quick sale to get to the next leven, that wont work. Trust has to come first.

This is where social media is a great opportunity to build. I would like to learn more about your business and professional service. If you want we can set up a free call for you. Just follow this link:

https://clarity.fm/paulanderie/vip-friends

Thanks for reading and have a great weekend,

Paul

Growth hacking is a process, so it can be applied to any professional service. I have worked with many consultants, coaches, and experts who rapidly test/discard/rinse/repeat strategies for growing their business.

First of all, let's agree on the definition of "growth hacking". In the recent years, the term growth hacking is used in the context of finding that one growth tip, trick, hack, tool, or tactic that will cause an explosion of growth in your business.

Growing a business requires defining a growth strategy and building a systematic, repeatable growth process, with the ultimate goal of achieving sustainable, authentic growth.

Coming to your question, technically speaking, growth principles and methodologies can be applied to any business model, not only SaaS. However, there are three reasons why it is more common to have growth discussions around technology startups.

1) To conduct meaningful growth experiments, you need enough data points. If your business is too small (e.g. you have 30 clients in total) how do you test something? Technology startups typically have bigger number of data points.

2) Having a growth process requires rapid testing of several growth ideas. If you have a brick & mortar business, it gets harder to test 10 different things a week. In a software business, this is much easier.

3) Building a growth process requires an investment. And that investment is viable if your business is suitable to achieve a scalable growth. If your business model is not a scalable model by nature, it's typically not worth that investment.

So to wrap it up, in theory, yes you can apply growth philosophy, principles, processes, methods to any business model including professional services. But in practice, it is more meaningful for certain types of business models like SaaS.