^ Yep, what Soyeong said.
The SG forums are full of people complaining about their contrib value going down. As many people point out there, if you're truly in it for the gifting, then contrib value shouldn't matter to you. But human nature being what it is, of course it does. Also explains when people find a way to take advantage of the system, they will. This is why there were hundreds of hundreds of giveaways for this weeks HB. If the people knew beforehand, they would not get full value for those games, no way there would be anywhere near the volume of KB and RO giveways there were these last 2 days.
Watch next weeks HB sale. Now that the SG admins have said they will not grant full value, the amount of giveways for those games should be a fraction of what it was this week and last week. Happens everytime there appears to be a loophole followed by complaints everytime the loophole is closed.