I've come across the same sort of exaggeration on eBay when I was buying LED bulbs a year or two ago. An awful lot of bulbs claim to be much, much brighter than they can possibly be; it wasn't uncommon to see `3W' bulbs claimed as outputting 500-600lm, which would place them at ~170-200lm/W. I was always disappointed with their brightness when I got them, until some googling revealed that, as a rough working figure, 80lm/W was more realistic. Once I started working on that basis, the bulbs I got were more in line with my expectations.