I have been writing about this for some time now and as other users stated and showed with their own examples it is usually arround 3-5%. You asked why no one is talking about your great rate for buying bitcoins. That is simply because more people use your platform to sell than to buy bitcoins.
Now when I have answered your question it would be nice that you answer mine as I am also curious as the user above me, what is the percentage you take from bitstamp rate? Or if you use another exchange rate which one is it? If you use multiple, which are those?
I think bitcoin users are the kind of people that like transparency. You are trying to hide your business model while at the same time saying it's definitely not 5%. Meanwhile users here bring out examples from your platform that it really is around 4-5%. You try to discredit people by saying the compare apple and oranges and by the number of their posts here. User above me has a lot of posts so I hope we will see an answer to this question.
what else do you know about our platform that we don't mate?

So easy to shout and blame, not so easy to build something..
Why do you keep talking about bitstamp? We were using them in the very early days, but that was ages ago. What engine we are using now, cannot disclose, it's sensitive information.
The issue is not your "formula" or secret code, the issue is that you bitcoin price is much worse than other bitcoin debit card suppliers offer and on average the margin is 4-5% over bitcoin price at main exchanges. Also if you agree that bitstamp price is lower (as you do now) why are you not using it to offer the best price for your clients? The fact is that your spread over bitcoin price at exchanges on average is 4-5%, so maybe you are using wrong formula or etc. I will start posting comparison of your price and at other providers in this thread to show your actual margin until you will agree with it.