Haha I lol'd at this thread.
On a serious note though, while if might make shopping on overclockers more appealing if they offered a free postage if you have X amount of orders as well as the forum posts, maybe it just doens't make business sense to do so. Yes you could argue, as I alreayd said above, it would make overclockers more appealing but I am sure there are quite a lot of people who would get free postage through the number of orders. Though possibly even if they offered free postage after some orders, someone would come on the forum and complain that their first order hasn't got free postage.
As also said before if somewhere else is cheaper then buy from them (and congrats on finding somewhere cheaper, you can have a medal if you like) Obviously depending on price but, for me personally, if the price on overclockers is higher, as long as it isn't a stupid amount then I would rather buy from here than some global corporation that doesn't give 2 S**ts about me or my order.
Finally, have you considered that as well as being a perk for forum users it is also works as an incentive for someone to join and get involved. Don't see it as "we offer free postage to our forum slave" but more "we offer free postage to those who offer advice on our forum, who get involved, who are in our community."
Slight rant here but I feel I have got to after the trolling in this thread. Are you seriously complaining that you can't get free postage on your order. I am sorry but when it comes down to it overclockers is a business and they can do what they want, no one forces your to buy stuff from them. If you don't like how they operate don't buy from here - simples.
Edit: Sorry, you said forum slave not spammer.
See thats where you are going wrong. You are basically going I am not going to do anything but I want free stuff.