[ikeboy]

A bond requirement after a certain amount of sales isn't a bad idea, but the threshold should be significantly higher, maybe over 50k or 100k in sales in a year.

A better idea may be to enforce the insurance requirement. This de facto requires sellers to commit a similar sum of money towards the business, but they're getting something for it instead of it being tied up. The Amazon contract says if you sell over 10k/month for 3 months then you must carry $1 million in liability insurance. The threshold seems about right, if they'd require proof of insurance for anyone over that threshold it would mostly fix bad actors using multiple accounts, while mostly leaving alone those that have legitimate business purposes in running multiple accounts.