However, after closer inspection of my blue clarisonic (the real deal, which I purchased from Sephora when I went to the states late last year) and the pink clarisonic (fake), I found quite a few differences.
1. The Clarisonic mia logo is different on the head. The "S" could have four curved lines surrounding it - two above the "S", and two below. On the fake clarisonic, the curved lines are in between the "S" and "O".
2. The registration number on the bottom of the clarisonic is different - font and orientation.
3. The word "Clarisonic" is missing on the brush cap.
4. When the brush head is removed, there is nothing written on the white ring for the fake clarisonic. The real clarisonic has got the patent number and some other symbols which I don't know. Furthermore, the real clarisonic has got three metal prongs, which hold the brush head in place. The fake one has only got plastic prongs.
5. When the bottom is pressed, there's a difference. It's a bit hard to describe but the fake one has a bit more of a harder click. The sound of the click is also different. The fake one has a more defined click than the real one.
I ended up getting my money back from the seller when I presented the differences that I found. She refunded me my money, told me to keep the product and closed the ebay listing. My brother is currently using the fake clarisonic, and I haven't had any feedback from him, so I'm taking that as a good sign. He is not using the cleanser that the clarisonic came with though. I don't blame him... Who knows what could be in that? I hope this blog post will help people who buy clarisonics from eBay to distinguish between a real one and a fake one.
EDIT: I have made a rather crappy video to show the two clarisonics in action, and the ineffectiveness of a genuine clarisonic brush head on a fake clarisonic.