All startups can (and will) benefit from growth hacking.
Growth hacking is a way of building your product or service, so that it is found more easily, used more often, and more revenue is generated. Your product or service becomes a marketing vehicle, through optimized user acquisition, onboarding, retention/engagement, virility, monetization, and revenue growth.
It is critical fro every startup's product or campaign is built to bring in new users, bring users back more often, a reason to invite their friends, and spend more money.
Dropbox is a well known example: their product was built so that if a user invited a friend to sign up for a free Dropbox account, both the user and their friend would receive 500mb of free space...and 500mb more for every new friend you recruit. After that, each user was given an additional 125mb when they would Tweet, Facebook, Email, or post on social networks. This hack gives the user more of what they want in exchange for free marketing, at very little cost to Dropbox.
Designing and implementing a strategic and data driven growth hack takes time and savvy. Make sure to work with a team of marketers that have a range of skillsets liek software development, analytics tracking, revenue/ROI knowledge, and design.