Profitable friendship

They are not just people you work with who use you as a one who can do a lot of job for them. They are also friends who befriend with you in order to get some profits of this friendship. It is actually hard to call such relationships a friendship, friends never act like that. Those people only pretend being a friend for you, though indeed they are not.
It is common for people to pretend like they are friends for you as it makes easier for them to use you for your own purposes. It is easier to make a friend do some job for you than to ask someone who is a stranger for you. It is impossible for such relationships to be a friendship, it is impossible for such people to be friends, it is better to get rid of such a friendship.
Such friends never greet you with some fests and even if they do, they greet you in the same way they greet other strangers. They rare ask you to come in case they have some kind of holiday at home and they rare spend their time with you. Such friends need a profit they get from your friendship but they don't need you. They can replace you with anyone else.
So, if you feel like your friend is using you it is important for you to analyze the friendship you have and to realize what to do. In case he or she always asks you to do him or her favor and never next to you when you need help – get rid of such a friend, he or she is not actually a friend for you.