To answer your question in your post that you deleted, YellowBrickRoad -- yes, I have done a summer gig before -- two actually, during my 1L and 2L summers, and I received offers from both of them. I hope you have, too, with all the "advice" you are plastering on these forums. When I said "everything counts," I never said to stress and become anxious over every little thing you do. If you've ever played sports before, then you know that everything counts in some sense or another. Like you said, "most" people won't notice if you don't send a thank-you note, but some may. Also, like you said, sending thank-you notes is the "polite" thing to do. Then why not do it?