Do you know for certain that your one day posting time is why people are buying from you?  If I want an item, it doesn't matter to me what the handling time is. I just bought an item that had a one day handling time, and they have take three business days to send it, and that makes me cranky. If they had said five days handling and sent it in three then I would have been happy.

I used to have a three day handling time on my listings, then the computer went bung. Luckily, it was fixed quickly, and I still managed to post my sold items within the three days, but it alarmed me, and made me realize that life is so unpredictable that any manner of things could happen to prevent me from sending out items within three days. For one, with a bung computer, I wouldn't even consider logging in on a public computer, as I am just too aware of the risks in that....But what if I had an accident and was in hospital, or the car broke down, or I was just too sick to get out of bed? Lots of other scenarios come to mind, so I have changed my handling time to

10 DAYS, and guess what?? Customers are absolutely delighted when I post in one day, which is what I try to do anyway, and I get feedbacks stating "quick postage" which anyone can see if they are concerned about the 10 days.  Also, anyone wanting anything in a hurry could always contact me and ask if I could send it quicker, and then I would explain the situation to them.

As a result, I have never had a late delivery.