Market

The market allows you to buy a specific egg or hatching potion with gems. As Alexander Augustin explains, the contents of random drops is, well, random. You are not guarenteed to get specific eggs or hatching potions at any time. Eventually, you should get every combination of egg and potion, but that can be a LONG eventuality.

The market lets you reward yourself with your chosen egg or potion for a reasonable price. Eggs cost 3 gems a piece and hatching potions cost between 1 and 5 gems, the base potion being the cheapest at 1 gem while the golden potion costs 5 gems.