Sorry…let me clarify. I think you misunderstood.
I did not mean for the hostess to write me a thank you note for the gift that I brought. Of course that is not necessary. In that example I was pointing out how I would follow up the next day with a thank you for the invitation.
The expectation of a thank you is mainly directed to occasions where I am shelling out hundreds of dollars as a birthday, bismillah, engagement or wedding gift.