The information currently available does seem rather conflicting.
On the one hand we have major carriers claiming that the Lumia 800 is doing well (not just in the UK but in Holland, France and Germany) and on the other we have this survey which says the opposite. I took a look just now at Amazon in their sim free mobile phone category and chose to sort under bestsellers. Ignoring all the feature phones and all the smartphones *significantly* under £400 we arrive at the following top ten. I do not get the impression that the Lumia is doing quite as badly as this survey would suggest although it is clearly not "setting the world alight". Other than that this little list does appear to confirm that Sammy has a great deal to smile about!
1. Samsung I9100 Galaxy S II 16 GB (Black)
2. Galaxy Nexus 16GB
3. Samsung I9100 Galaxy S II 16 GB (White)
4. BlackBerry Bold 9900
5. Apple iPhone 4S 16GB Black
6. HTC Sensation XE
7. APPLE iPhone 4 16 GB
8. Nokia Lumia 800 (Black)
9. Motorola RAZR
10.Apple iPhone 4 16GB Black Factory Unlocked