I don't see any cons with that except they need someone to do the job, Having an active Facebook page is a very great idea to attract more people on Facebook who have interest in making memes, Imgflip help you make memes and reward you with Imgflip points and I can say this is the best meme maker in the world, In my views, the reason why Imgflippers isn't as many as Reddit, Even though Imgflip is better because they only have few advertisement or ways to promote this app/website. Aside from an active Facebook page will promote this app/website they can also earn money if they achieve many reactors and likes...