First let me start by saying that is impossible to guarantee any certain percentage in growth.
Growth hacking is about viability, not traditional marketing alone if at all (depending on your GHacker)

When it comes to growth hacking, the GHacker is responsible to helping tweak all parts of the business from pricingn to management styles, product/service development ( is not about what your market hears, but what makes them truly want to share your culture, product, and their rxperience with their friends) and once you have them as paying customers what's their K factor (conversion rate of their fellow friends).

The "magic" of GH is that it embeds virability into your products making it not only enticing to share but easy and rewarding. GH is about unthinking traditional marketing with a low budget, measurable conversion and fun approach to gaining new customers and their friends. Is not about simply increasing a budget and exposing everywhere.

If you would like to brainstorm and evaluate your clients' situation better give me a call :)

Fellow Growth Hackers,
-what else would you add?
I don't want to assume and answer with ideas (the way traditional marketers would do) but I'm sure we all have something to add :)