I had at most 20 hooded orioles come to my feeder yesterday (I put it up the day before yesterday), and today I haven't seen one visit.?

I bought a hummingbird feeder on 6/10/15 and put it up the same day. On the first day no birds came to it (which is what I expected anyway). The day after 6/11/15 I had at most 20 hooded orioles and a few hummers come, I was shocked to see so many. And today 6/12/15, I've seen a few hummers but not a single hooded oriole visit. What happened, did I do something wrong?

Its on the same spot as yesterday where many came, in the middle of my backyard on the grass, hanging on a double shepherd hook.

I purchased this feeder:

http://www.homedepot.com/p/Perky-Pet-8-oz-Pinch-Wa...

And this nectar:

http://www.homedepot.com/p/Perky-Pet-2-lb-Hummingb...