Goodbye: thanks for visiting.
Wait! - let me rephrase that - - a 'visit' is when you show up at my door and I make you a coffee or pour you a cold beer or a scotch, and coax the dog off the sofa so you can sit down.
A 'virtual visit', like this one, ought to have a different term, or spelling, to distinguish it from the real thing. I'd propose the following:
(with the first 'v' silent).
So once again:
Goodbye: thanks for vvisiting.
me a note if you want to - I usually write back.