There are a bunch of large corpora containing millions or billions of words.
My needs are simpler: I only need the 20K most used words. Preferably, these words should be most used in the general social media population, but any corpus will do as long as it consists primarily of words used in the last 10 years and as long as academic journals don't count.
COCA looks good but has more words than I need and costs more for a commercial license than I'd like to pay.