A house elf is a friendly troll but does not bite you on the leg, only makes sometimes annoying noises.
Just like mom at home, they are generally not paid. They tend to do several things at the same time, such as chatting on the phone to their friend, typing on a keyboard, supervising the kids work, thinking they should not forget to make the pie for dinner, and paying the phone bill; thus forgetting sometimes that apples are necessary to make an apple pie.
Paid trolls think they are great consumers, because they have time to go shopping while the babies elves are at school. For this reason, they are good cible for advertisment and primary victims of propaganda. They are generally dedicated to their family, both because it is their duty, their role, and their fullfilment, but also because they have no revenu themselves, so are just tied to their employer.
Do not forget to pat your house elf, feed him crumbs. But no new socks !