My mom has had a fitbit for at least a year now, and she really loves it.
Unfortunately, she has lost one fitbit already due to the band coming off while she was wearing it.
She replaced it, but the band would still catch on things and pop off occasionally. It got to the point where she was constantly checking her wrist to make sure it was still there.
We came up with a really simple solution to keep the band from falling off. She wanted something that was easy to do herself (aka one-handed) and that would work.
After playing around a bit, this is what we came up with, and she reports it works great!
Close the band up where you normally wear it. You will need to mark where you put the new hole.
The pin will go through one of the precut holes and into the new hole you have created.
The pear-shaped (or coiless) safety pins are so inexpensive at around $2.00 for 50 that you can keep a pin on every color band you own!
No more worries that your fitbit will fall off while you are out getting in your steps!