It's a marketing word...
The thing that would bother me the most (besides the title teacup) is that the dogs are used as an accessory, and typically have heath problems...or even worse, people try to bread the little babies. It's concerning to me that they are so small. What is a "safe" small size for a Yorkie, anyway?
I think my Trixie will be about 5 lbs. I was really looking for a 6 lb baby.