Lots of companies do keep their arbitrage tools secret. There is a much greater efficiency in operating a SaaS over a full-fledged business, since the SaaS has

Lots of companies do keep their arbitrage tools secret. There is a much greater efficiency in operating a SaaS over a full-fledged business, since the SaaS has almost 0 marginal costs, so every additional $39/mo requires nearly no work. In contrast, generating $39 in profits through arbitrage requires at least some work and has risk. If you buy a product and sell it to a person who gets a refund, then you lost money.