On the other hand a mechanism of a number of online market place scams is to gain customers trading on the “security” (such as it is) of the market place, and then directing the customer out of the market place. Everyone (should) know that any eBay seller that tries to get you to complete the auction outside of eBay is likely to be a scam. Likewise I would hope anyone would be leery of placing an order on Amazon and having a seller contact you asking you to cancel that order and buy it cheaper on some other website. Reputation matters for consumers, and legitimate sellers rely on the market place’s good reputation to help smooth the sales process. Scammers do too, but their goal is to get you out of the market place ASAP where the rules and regulations are harder to get enforced. Companies like Apple and eBay have a strong incentive to have a trustable pipeline and mandate sellers to use it because even though they’re not the ones perpetuating the scam, being known as a market place where scammers hang out is damaging. Consider this, between the Apple Store, eBay and Craigslist, what order would you place those market places if ranking your level of trust for not getting scammed when providing your payment details for a recurring subscription to a random seller?

Or put another way, even though it’s free and plenty of smaller companies do, Netflix doesn’t make posts of Craigslist advertising their services. There’s obviously many reasons for that, but at least part of it I’m sure is no one should trust a random link in a Craigslist post to a Netflix sign up site.