If you've taken the time to build an email list, then you should use that opportunity to survey your subscribers. Consider asking them, specifically, what they're most interested. I recently did this and the answers actually surprised me. However, another thing the answers did was allow me to laser-focus my affiliate offers in the right direction. This is invaluable information and it's coming straight from your list.
The reality in affiliate marketing is that it's like most other work-at-home ventures; there are a few who are filthy rich, a good number who are successful enough to meet their goals, and a ton who aren't making anything. So, the question isn't really whether or not affiliate marketing is a viable income option (it is), but whether or not you can make affiliate marketing work for you. Only you can decide that. But to help, here are some tips.
A “viral” product is one that is designed to spread (often quickly) to a great many people - this can be a great way of getting your affiliate links out there without ever having to create a website. You can produce a short 30-page eBook or a "special report" on a particular subject, insert links to affiliate products into it, then distribute your book through whatever means you like – you could tell people that they're welcome to give it away, sell it or put it on their websites. You can kick it off yourself by selling the eBook on eBay for a small amount.
Win-win-win. The advertiser wins because they only pay when a purchase is made (as opposed to the shotgun approach of paying to advertise to the masses and waiting for a small percentage to actually buy). The affiliate wins because they make money while providing helpful advice. The customer wins because they get a trusted recommendation for something they might not otherwise have known about.
While any “regular” job requires you to be at work to make money, affiliate marketing offers you the ability to make money while you sleep. By investing an initial amount of time into a campaign, you will see continuous returns on that time as consumers purchase the product over the following days and weeks. You receive money for your work long after you’ve finished it. Even when you’re not in front of your computer, your marketing skills will be earning you a steady flow of income.