The short answer is that you don’t need one. Ad platforms are very simple to use in 2021 and it is often very easy to get ads up and running. The reason why you may wish to use an agency such as Red Cow Media is to ensure that you don’t waste budget (which is very easy to do), you get the lowest cost per click or cost per swipe, and you are able to create an effective funnel system to collect and store customers at different stages of the purchase process. This improves your ROAS substantially.