When I put one in the Roku 3, the pins faced *up* toward the ethernet port.
Regardless, never try to force the card into the slot. If it is put the way the slot requires, the notch will line up and the card will go smoothly in. If you are trying to force the card into the slot then the notch isn't matching. Also, once you get the card about 80% into the slot, you may feel a soft push-back from a spring but it should still continue to go in smoothly. It still should not feel like that card needs to be forced in. For the Roku 3, once it was correctly put in the slot it clicked into place and the Roku prompted for if I wanted to reformat the card.