If you are a small business owner/operator, you need to avoid one of the oldest and easiest mistakes to make: putting all your eggs in one basket.
If you have a client/customer who forms a disproportionate portion of your sales, you are in an immensely vulnerable position. They can really put the squeeze on you and in an uncomfortable position.
The same principle applies to any platform you might generate most of your sales from. If you are overly dependent on one publication or website and you fall foul of their terms and conditions your business can be wiped out overnight.
I have met an individual recently who has experienced this at first hand. And, consequently, his business is hanging in the balance.