Contact the company directly. If you use a product or service and want to recommend it but you can’t find evidence of an affiliate program, consider approaching them and asking if they are willing to set one up (maybe with your help). Highlight your audience and the value of your recommendation. Explain that an affiliate program is simply rewarding happy customers (you!) for promoting, and they don’t have to pay until a sale is made.
Sign up for a reputable affiliate network: Aside from Amazon, there are dozens of large reputable affiliate networks, such as Share-A-Sale, Clickbank, and Skimlinks, that specialize in connecting you with merchants who are looking for affiliates to sell their products. They charge relatively low commission fees for the privilege of connecting you with merchants, and the merchants on these sites tend to offer much higher commission percentages or set dollar amount payouts.
If you don’t mind doing other people’s chores, then TaskRabbit is a great option for making money online. Earn extra income by walking your neighbor’s dog or mowing Mr. Smith’s lawn. It might seem like not the most lucrative option, but the top taskers reportedly earn as much as $7000 a month, making this a full-time way to make money online for some.
If you have pop-ups and optins on every page, I would have to think that it would be a lot harder to convince someone to link to it. Especially since the pages where you have your optins (and probably receive the most traffic) are probably the same pages that you have your best content on as well that you'd be hoping to pitch in your outreach campaign.