It's the slightest bit inconvenient. It takes time to handwrite it, ensure you have the correct postage, walk to the mailbox, send it in the mail, and wait for it to arrive. You could have texted or emailed or phoned, but you sacrificed the slightest bit and that feels important.
In such an age of technology, part of me is surprised we still have mailboxes. I receive so much spam/advertising mail, most of my bills are paperless. Does anyone else get that jolt of excitement when something personal arrives in your mailbox? It makes me want to check the mail every day, just in case.
Today, I made a simple thank you card for a friend.