The game sends spam to your contact list or social media account.
Friend Spam is when a game automatically posts to your social media or emails people in your contact list without your knowledge. The game may even send these messages posing as you. Because your friends think that you are personally endorsing the game, they are more likely to download the game and give it a try.
Another form of impersonation is when the game uses your friend's names and pictures to falsely represent actions inside the game. The game may send you a gift and say it's from a friend, but your friend never did this. This tricks you into thinking that your friend is playing the game frequently, which may make you play it more frequently. It may also make you feel a need to reciprocate with a gift.