I have an online store and sell in a couple other venues online. There's only a couple banners I sell, for a niche market, and over the last couple years have only sold a handful of that banners... but I charge a lot for them too.
We sell windows films mostly, automotive, residential, commercial... tint, UV protection, Privacy films, Anti-glare films, anti-graffitti films...etc.etc.
We do pretty well and things are growing, but it's been pretty intense keeping up with the technology and keeping the layouts and graphics up-to-date and not looking like they're from the stone age.
Unless you do you own webdesign, programming, and trouble shooting... it can be very expensive to actually operate a webstore if you want it to be dynamic and easy to be on / shop on.
Also, be prepared for a total disappointment in humanity when , what will seem like, a large portion of people try to lie to you and scam you in order to get free product.
When we first started we didn't put delivery confirmation on anything. Seemed about 20% of them "never arrived". Now we put del. con. on everything and we hardly ever have non-deliveries anymore and the complaints we do get for them are usually stolen or misplaced mail issues.
And, as another above me said.... getting placed on google is difficult. It's not that hard to get into the top 100.... but you really need to be in the top 10, and preferably in the top 5 to really get any good traffic. Otherwise, it's very expensive to advertise online. And can be very competitive. Read some books on SEO techniques, and use only WHITE HAT....
Just look at people selling corplast signs online.... $1.50! Sure, shipping and a holder are extra... but still. I can't compete with that.
Anyway....
I say give it a shot if you want. Getting quality traffic with no or low cost to you is the hard part. At the very least you can incorporate your website into your local advertising and maybe make sales with never even talking to the customer.
Every business should have a website and incorporate it into their advertising, even if just to tell somebody who they are and what they can do.