Originally posted by Dynamiez:

Sorry to ask... but what is this obsession with achievements? does a game get any better with them? you only see them when you are NOT in the game... never understood why people ask if they can be added...

some sort of:
"i dont like apples.... oh wait! there is a sticker on the apple. now i buy it!"

Apples with stickers is not a good analogy.
What achievments provide are goals which might extend how much certain people can get out of a game.
Take Kerbal Space Program for example, unfortunately it has no achievments. Some people might try to land their rocket on a certain planet just out of curiosity, some other people won't even try because they feel that with the lack of goals there is no game to begin with (and that's also why so many people struggle finding enjoyment in sandbox games)
So an achievment is a challenge, that extra push some players might use to discover some fun they wouldn't have otherwise found.
Say Kerbal had achievments, I wouldn't have landed my rocket on that planet, but since you challenged me to do it, I'll show I can, and maybe I'll find some fun along the way too.

You can also see them as a "checklist" for people that like to be organized and want a checkmark on every activity to make sure they've experienced all the game had to offer.