Setting up a free Cloudflare account is a must for any website. It’ll add a performance boost and security with almost 0 effort. One tweak I recommend in Cloudflare is turning your wp-content/uploads directory into a fully cached directory using page rules. This means Cloudflare will serve all images from cache acting as a free CDN plus it's very simple to set up. Once you have the budget you can spring for the $20/m Cloudflare account which will automatically compress your images on the fly.
You should also make sure you aren't competing with your own affiliates for eyeballs. Any marketing channels you're using, such as search engines, content sites or e-mail lists, should be off limits to your affiliates. Put marketing restrictions into your affiliate agreement and notify partners immediately. It's your program--you set the rules. Or, if you prefer, you can let your affiliates run the majority of your internet marketing.