A: Hey,

Free websites and websites on which you connect AppSumo code are the same, just different limits, such as CMS items, form sumbissions, bandwidth etc. Free websites are great for small websites up to 5k visitors a month, 10 pages and 50 CMS items.
If you need something more than that, attaching AppSumo code to that project is a great idea.

So basically with AppSumo codes, you are buying limits for project, 1 code can be activated on 1 project, and that project will have much higher limits that a free plan.