I was in town yesterday doing some Christmas shopping, and I stumbled across these Christmas LED lights in one of those temporary Christmas shops. £3.99 for a string of 15, 3 strings for £10, and they looked like the ones you can get on eBay for a lot more. So, I took a gamble and bought 9 of them! Got them home, and after some work getting the glue off the control box, found that it was quite straightforward. I couldn’t see the chips inside each pixel clearly, but a process of elimination and a hunch told me they were likely WS2811 based. Now I’ve cut the wires, wired them up to an Arduino UNO, and with some testing I’ve found that they are WS2811 running at 400Khz, so now I’m in possession of some nice and cheap strings, very happy 
Great find! What did the packaging look like, and what were they called? I wonder if they’re findable on the Internet in this form…
cheep cheep cheep! great find!
i especially like the £ symbols in this post! 
For the US folks in the audience, that’s roughly US$5.50 per string (right?)
How long were the strings? How many pixels?
Presuming that the £’s are because you are in the UK as your profile indicates, where, by chance, did you discover these items?
There are 15 pixels in each one, but if you open up the last pixel you can string them together to any length. They came from Basildon, Essex, UK. The Christmas shop near Toys R Us for those who know the area. Funnily enough, they weren’t that popular with the “normal” shoppers! They had about 100 of them left on Saturday…
Goodness me Mark, that was fast and impressive detective work! That’s the place. I’ve added a post with the box details for those who’ve asked (wasn’t sure if I could add pictures to this post so I did another, sorry if that’s considered spamming). Probably not much use for those of you residing in MA though, probably a bit of a long journey 