Some include a physical or vocal component, like Blacker Lotus or the Gotcha! mechanic on Touch and Go, some have rules that specifically reference flavor text or artists, like Carnivorous Death-Parrot and Drawn Together, and some require interacting with people or objects outside the game (Ashnod's Coupon being my favorite)
All 12 magazines were owned by Shogakukan, the publisher of Pokmon Adventures and CoroCoro Comics
According to PWCC, though, a graded 9 version of the Venusaur #13 Black Star Promo has sold for as high as $420, and recently averages for around $320
If players open this card in draft, and they're already considering Black as a color, this card should easily persuade them to commit
It is more generally used as a way to keep the gameplay fun
(I am selling this item in tears because there are some cards I want to collect in Pure