That's it really. If you're grateful for something, just write thank you or thanks. Writing ty means "I can't be arsed to give you more than a nanosecond and I'm too busy for manners."
I see this a lot on FB and in emails and texts and I can't help thinking "Nobody's so busy they can't write a word!"
What's the world coming to? I'm hoiking a heck of a bosom here.