Ooh I have one and I love it. I get a new charm every so often for birthday / anniversary / Christmas well any excuse really. Just recently got a strawberry charm from my boyfriend.
And they are easy for people to buy for you if they are stuck for gift ideas. Charms start around £15 and can get really pricey. Some of the cheaper ones are my faves though. I'd love the snowflake one next Christmas.
Xxx