Feeling obligated to return a favor, share resources, trade an item, etc.
"Coins can be gifted to people on your friends list, and most will expect you to return the favor."
"This game is heavily focused on trading. You can trade pets and accessories with other players. Getting a profitable "good trade" is one of the most addicting features of this game, next to the chance of hatching the rarest pet from an egg."
"During the team events where you pick a side you can give energy out to your team mates. You have 3 free drinks that also replenish once per day. I like it."
"There are some advantages to have friends helping you daily, but you are not totally compelled to do it. I don't feel like I would be missing out that much. Also, you can add random friends easily, you don't have to know them."
"When you friend other players in the game, you can sell and buy resources from one another."