A term borrowed from the gambling world to refer to higher rollers that drop a lot of cash and make casinos a ton of money. In Silicon Valley, whale refers to high rollers in mobile games. Zynga, Supercell and other mobile gaming companies make most of their money from whales as less than 3% of freemium game players spend any money on in-app purchases.
Richard: Lets make our game free so we can attract the most number of downloads and hope that a good percentage of our players convert into whales.