It say nowhere in de Dev diariy it only is buffing the unbuffed building. So it only equil in buffing with the Hot Dogs. So as other said first it is almost a GEMS SCAM. If you play 24hrs you can not get 8000 present or more, i have the numbers not exactly,. If you already have it say you have bought a lot of GEMS or are in a big Guild and you could have a huge stockpile to trade for the presents. Otherwise with regular playing it is not giving a good buff.