What made me first consider making a Thank-You was how excited I was about new subscribers. Subscribing feels like more of a compliment than Following on other social media, for some reason; it's someone specifically saying "I want to read your comic now" and I wanted to express and acknowledge how cool that was!
I found and read through this older thread while I was making up my mind and saw that, while there were one or two people who didn't like them, the majority of people were really excited to get art on their walls, and that cinched it for me!
I have a note in my profile saying that "I leave thank-yous but feel free to PM me if you don't want one," and I also always check to see if there's any notes in the subscriber's profile saying they don't want/prefer thank-yous. I just want people to know that I won't be insulted if they'd rather not get it on their wall, but I also don't wanna guess and accidentally leave someone out! ;u; I also try not to respond immediately, in case they subscribed by accident or change their mind quickly. xD
I was gonna do the "add the person's name so that it's personal" thing but it's hard for me not to feel a little artificial doing that, so I left it out and just type a thank-you message along with the art!
I've never gotten one myself (my reading list is very small), but I'm definitely not opposed! And it's pretty cool to be able to find new comics on other people's walls, so I like the tradition a lot. ;u; I definitely think it would be nice if Tapastic implemented a "pinned post" like twitter has, though; I can understand being frustrated at official announcements being buried under thank-yous.