If you are looking to diversify and not put all yours eggs in the same basket, there are a lot of alternatives out there. One of them are the Facebook groups. Many sale groups have been popping on there. Some are local sales group, some are more general and some are very niche.
I currently belong to two of them, these are well managed. I sold a few things, odd stuff I had laying around for a while. When you join such groups, it is important to read and follow the rules. Each group are different with their own set of rules.
The groups I currently belong to are:
Yesterday's Treasures Picked for You
Second Time Around Vintage Linens
If I join other groups and find them well run, I will add them to my list. If you have a group to suggest, let me know!