Every two-sided marketplace faces the same brutal problem on day one: nobody wants to be first.
Distributors won't join if there are no shop owners. Shop owners won't join if there are no distributors. This is the cold start problem — and it's killed more startups than bad code ever has.
The Sofasto Approach
My strategy: seed the distributor side first, make the app useful for them even without shop owners, and let the network effects follow.