Last year, a friend of mine has approached me for a web app with 4.5k USD for developing and deploying the idea. Knowing I was getting lowballed, I didn't push back as I was temporarily unemployed at that time. The initial timeline was 3 months.

The product had search, geolocation and simple payments integration, discount promos, account types and criteria-based automatic account upgrade and a few other features.

Development stalled after 3 months as I was burned out having to constantly lookup information on new features. My estimation at the time showed that about 60% of the product is yet to be developed. I got paid 1.2K for the work done so far.

Fast forward to this day, my friend approached me again saying he wanted to do a partnership model for this product. I would be solo dev dealing with remaining product development, vps management, training support ops, bug fixes and patches, delegating ui design and he would deal with marketing, operations, strategy, dealing with customers etc.

He offered me 15% initially and accepted to go upto 25% after I put up some resistance. I am not putting in any money into the product. Whereas he is putting down money for getting the word out, managing operations, marketing and advertisement, hiring support ops, and meeting and dealing with customers. We are in good terms, but 25% for this product felt a little low.

Apart from product dev, vps management and training support ops team itself is a huge time taking effort, not to mention feature addition once the product takes off eventually, but I am struggling to put in words why even a 35% is justified. Also what if a feature he envisioned doesn't really work and needs a quick(er) overhaul? He did mention that if the product makes good money, then some revision can occur to the accepted percentage.

Is this percentage low? If so, how do I communicate effectively? I would love to hear your thoughts. Thanks.