My wife has a small business similar to yours, and I ended up building a micro CRM for her, complete with scraping (some of our vendors don't offer an Api), reports, invoicing etc.
My story is similar. My friends wife was selling Indian women clothes and I took a stab at re-jigging her business for the "messaging-first" world. worked like a charm. she is now selling a very non-differentiated product at the rate of 1 every 20 working minutes. :-)
so now we have good problems to solve like actually needing a CRM, invoicing etc that I hoping to do via a web app.
Once that is done, it could be sold to other similar businesses. I have already done some presales using my mockups and there is interest.
you should just blog about whatsapp selling and sell your services; other than selling to Chinese on wechat I have no idea what this even is or how/why it works.
below you said you are running whatsapp sales for b&m shops, but how do customers find you? afaik whatsapp has no discovery features.
It streamlined the process significantly, lowering the total "handling time" from a couple of hours to ~10-15m in total, which freed up time to tend to custom commissions from clients.
I don't have serious hard numbers before that, as the CRM saw its first commit around sale #6.
so now we have good problems to solve like actually needing a CRM, invoicing etc that I hoping to do via a web app.
Once that is done, it could be sold to other similar businesses. I have already done some presales using my mockups and there is interest.