You could try advertising more, for example, by putting up signs around the neighborhood, posting about it on social media, or having people you know spread the word. You could also try doing it in a different neighborhood that might have friendlier people, or do it in a time and place where there's likely to be a lot of people walking around the area (e.g., near a church before the end of a mass).
Clearly, there's a lot of demand on Amazon, and if any product is going to sell, it's going to sell well on Amazon. But the goal here is to source the right products that will easily sell at the world's largest online retailer. Generally, products between $10 and $50 sell very well here. Just be sure to do the right market research before jumping on this bandwagon.
Mechanical Turk: Amazon's Mechanical Turk is a resource for doing human-intelligence tasks, or as the site commonly refers to them, HITs. You get paid a very small fee for any given HIT and you'll need a good deal of volume to make a substantial amount of money. But it is a resource you can use in your spare time to generate a small income online.
I have found that one size doesn’t fit all. Rather, specific types promotions of particular products work well with Amazon. I have also had some success by getting people in the Amazon door for other reasons. For example I’ve experimented a couple of times on dPS with running a posts that gave readers a hypothetical $1000 to spend on photography gear and asked them to surf around Amazon and choose what they wanted to buy. The result was 350 comments (a fun community building exercise) and quite a few sales and commissions!
Ebay is a bellwether. It's been around since nearly the start of the online boom. But, like any other platform, success can seem fleeting if you don't know what you're doing. Selling items on eBay, professionally that is, can be an art form. Getting people interested in your auctions isn't always easy, especially when there's hefty competition and low demand for what you're selling.
Provide excellent customer service. Answer any questions buyers post as quickly as possible. Be professional and courteous. Positive communication builds your reputation with buyers and gets you return business. Also, package your product well and ship it out quickly. Allowing an item to become damaged or taking too long to ship can negatively affect your reputation among buyers. Wrap all items, especially fragile ones, in appropriate packaging. Commit to shipping items as soon as you receive payment.
Understand how a niche website works. A niche website focuses on very targeted, specific information. The content must be specific, useful and interesting to your target audience. Successful niche websites get anywhere from 1,000 to 10,000 visitors per month. You build content on a particular keyword, and you make passive income with Google Adsense or through affiliate links.
Webinars are quite possibly one of the most potent ways you can make an exorbitant amount of money online. You'll need an audience to train and you'll need to know what you're talking about. Of course, this usually requires having a website and some semblance of an online presence. However, people can still do webinars without all of that. For example, you might have a sizable social media following and you train them every week on something to do with social media. But you will need a product to embed and sell at some point. Don't worry about it in the beginning. In my experience, the best webinar platform out there is GoToWebinar.