That's still sort of pointless because you need to generate a ton of turnover, which increase costs (credit card processing fees) and generally raises suspicion. With a carwash you might only need 1000 fake car washes at $60 each ($60,000 turnover) each to launder $50,000, but with the amazon gift card scheme you'll need to do $250,000 in turnover which is suspiciously high for a small business selling gift cards.
$250k per month is $3 million a year. That's not high revenue for a mom-and-pop online reseller. Especially given the margins for typical resellers. Plus, it's far more efficient than something like a car wash. You can have one automated platform that sells through various businesses to keep revenue figures where you need them. So if you want to stay under $50k/y revenue, then split the sales among five various "companies."
With a car was, 1000 washes, at 5m per wash is 84 hours of active operating time. This creates an upper limit on the amount of money that can reasonably flow through the company, since 84 hours is roughly 3 hours a day of utilization per month. You might be able to get by with about double that many washes without raising suspicion. But all it takes is a peak at the company's water bill to determine how accurate that figure really is.
Plus the operating expenses are much higher, as it requires a specialized building, land, etc. Whereas the online retail requires a computer and some software. It's easier to move and hide. There's just so many benefits to using online retailers over brick and mortar operations.
Not necessarily gift cards. But $3 million in revenue is right about the time a small online business can afford to move from the garage to a dedicated space with staff. I would expect that Ebay/Amazon/etc all have many resellers in that $1-5MM revenue range.
