Its my first week ever using KS we launched our project last week and this morning it was set as a Staff pick and we got 5 new pledges the next few hours after. So i think it maters as it helps the kick starter get more noticed on searches. i have no idea if i should put that sticker on my promo or not as i don't have any room on it and I was thinking the same thing like you that i don't know if people care or not if its a staff pick. What staff picks do is mainly create more visibility i think.
I think people would care more about things like
Kicking it forword ( i just added that to my page as we are planing to give 5% back to other kickstarters once we finish our funding).
i added it to my forum signature but no idea