How do you know if you should be using Affiliate links on your site or PPC ads...or both? I'd appreciate it if someone could explain a basic strategy for me.
It all really depends on your site's niche. Obviously you wouldn't use affiliate links on a site that attracts teens as they likely don't have access to a credit card (or other online payment methods) to buy products with. You have to remember that with affiliate links, only a very small percentage of clicks will lead to a sale (unless the traffic is extremely targeted and the landing page has a high conversion rate), where as with PPC ads, you earn off every click. If you're still stuck on which to use, you can experiment with both. Just ask yourself how much you value your visitors and whether or not you like the idea of losing them for the sake of $0.10 or the small chance of a $20 commission.
Depends on your sites primary audience. If your site is about buying stuff then affiliates is the way to go because it will convert better into sales.