Why is Necro'ing bad?

[Kittie]

Well personally i don't see a 'big' problem with nerco-ing, as a forum junkie i read pretty much every new post (even went through the archives partly :D) unless i'm to tired to go through them all. Anything that has useful information isn't to bad bumping/nerco'ing over. However, i could understand that its a bit pointless to necro a buy/sell/trade/auction thread if hasn't been active for a few months/years