The ease of use, ability to create custom campaigns with multiple channels in one campaign! I also like that they offer an unlimited number or keywords per ad group (as opposed from Google's limited amount).
Also we have been able find our way around their product very quickly which makes it easier when you are trying something new every day as well since there aren't many things out yet at this time compared other platforms such as google ads 360 etc.. We can set up all advertising types within seconds instead having them load each type separately so now its just 1 click vs 10-15 clicks depending upon what your doing currently!!