From an inventory perspective, yes. =)

But -- you still need to get people coming to your site somehow, which is actually the harder part.

You can buy ads, do social media marketing, blog posts--lots of techniques. And there are a ton of services for that. I've experimented with many, and continually try to refine that aspect of the business, but I can't claim to be an expert yet.

I reply to emails every day. Once you get orders, you do need to check and make sure everything is going smoothly, and ensure that your customers' needs are met.

I also get a lot of emails asking for advice about various upgrades, fixes, product recommendations. And these often lead to sales, as long as I have something that works. Depending on your store, there can be a consultative aspect to it.