$100 is a relatively small budget for running Facebook ads, and it can limit the scale and reach of your campaign. However, it’s still possible to run a successful ad campaign with a $100 budget.
Our advice is to focus on the right optimization. We have the best results when optimizing for purchases and broad targeting. You need to tell the algorithm what you want from your ads, so if you optimize for purchases you get purchases, and optimizing for the traffic you’ll get traffic. The leads that you’ll get with traffic optimization won’t become your customers.