Well Im gonna buy it and try, i saw 4 months old youtube video where guy testing asic usb miner with only 330 mh/s earnings - (0.0054BTC a day) with 15 gh/s must be more. I saw new usb miner gekkoscience, if its useless then why they selling it?
Nobody is making $38 USD a day on an old USB Block erupter. That is what you call a bald face lie.
You do understand that people who post You tube videos make money off of advertising right? They'll say anything to get views/revenue.
It's also possible he was mining some new sha256d altcoin and then cashing it in for BTC. But if you want to trust a Youtube video over a modicum of common sense then by all means go ahead. At least you'll have learned something first hand. And USB miners don't consume allot of electricity as some other alternative learning methods do.
Have fun.