While vending at shows they've given out copies of Mine Collapse free in goody bags
the second stage lets you pay two mana and tap it to create a 0/0 colorless Construct artifact creature that gets +1/+1 for each artifact you control
It is a bit like Aurelia's Fury, very occasionally you still want it but overall it is just slightly too expensive to be convenient
For those newer to Magic: The Gathering, the whole point of Jumpstart is speed: take two boosters, shuffle them together, and you have a playable deck with all the Lands already included
The main reason for this is that you have to pay a weekly fee in the form of a rental subscription to be in a position to short cards in the first place
It may not be the most reliable of the two for ones, not even always the best value of two for ones, but it is often enough and when it is it does tend to end the game