Unless you have a decent traffic or hugely demanded items larger comps might no be interested.
Access to market is what leads companies to buy one another. I rencently bought a commercial cleaning company and merged it with my residential one to create an improved service with my people but leveraging the other company's subscriptions.

I would not buy based on services, but buy either access to data, people or market. So your approach can be based on that rather than pitching a retailer with zero margins.
Finding companies to pitch to is harder than it sounds and it literally simply comes down to you picking up the phone as much as you can.

Good luck!