In the game Zombie lane many missions, bonuses and achievements are focusing on having neighbors and visiting them to help them, send them presents and requesting their help in achieving specific targets.
Neighbors are players who also play on the same platform or website and those players their username can be added so they become visible in the game and are sometimes referred to as friends, sometimes as neighbors throughout the game.
The game has a variety of different platforms it is build for, which allows interaction between players in various ways. Some sites have a tweet like communication system, while facebook allows for more elaborate interaction.
There are also weapons which require neighbors to be added in order to be unlocked.