"A boat's a boat, but the mystery box could be anything. IT COULD EVEN BE A BOAT! You know how much we wanted one of those." - Peter Griffin
For $10 with free shipping, you can buy "something" at somethingstore. You won't know what it is until you open it, but it's most probably new, and possibly a gadget or electronic equipment. Then again, the site explains that "you can be a 25-year-old man and your something maybe [sic]a white tank top embroidered with a pink heart." Still, way more fun than a gift card.
AU: This is US only, but it's still an awesome idea.