~snip
I guess it's boils down to good customer service and then promotions and marketing as you have said. Yeah, you need to offer variety of items. For example if you are in the shoe business, then you should have at least full sizes of the shoes that you are selling.
So talk to your customer, get feedback so that you can improved. They are the life line of your business, so obviously, you have to treat them very well. I also have online store that born out of the pandemic, and if I may add about the negatives though, there are competitors out there that wanted your business to be destroy so just be careful on who you deal with as well, just saying. Because as much as you are customer centric and giving rewards and discounts, sooner or later they will give you bad feedback because the people that ordered from your is from your competitor.
Quality and competitive pricing are important in business, but in my opinion, customer service is even more important if you want to increase sales and profits. As a customer, I prefer to go to stores with a good service attitude even though the prices may be higher than in other places.
In business, we should sell what the customer needs rather than what we have. I mean we should have many different models and based on the customer's attitude we should behave appropriately. That's something I take very seriously as a customer.