Hi Ollie!
Itay from Shoffi here.
I will reply to some of the points raised here regarding our platform from my point of view, and I hope it will help you make the right decision.
Shoffi, just like other PRMs, is a technical tool to help you manage your partners’ programs. It can’t guarantee success or make this channel successful just by signing up.
A good partner program requires time, connections, and work; like every business relationship, it has to benefit both sides.
We see many partner programs on Shoffi, and the most successful ones are those who take this channel seriously. Some have a partnership manager who takes care of partner-specific newsletters, events, and customer success.
Saying that, we do the most we can at Shoffi to create new connections and opportunities with our market and, soon, with the Shoffi Network. But that won’t be enough if your app is not useful for the partners or your offer, whether financial or other, isn’t beneficial enough for them.
In the long run, partnerships are the most cost-effective channel for apps (as a previous Shopify app owner myself), but unlike PPC channels, for example, you don’t just pour money and start seeing results; it’s a long-term game.
If you are worried about costs or if it works for you, start a partner program manually with a simple form and spreadsheet tracking. Contact your best users or agencies you know using your app and offer them to join. If you see a potential from their interest and what you can offer, then it might be worth checking a PRM solution.
I hope that helps 
Itay from Shoffi.