Actually is it akin to shoe.com and shoes.com not buyshoe.com or buyshoes.com.
One is a US international clothing company which has trademarked a clothing range like shoes.com and the other is a UK international bank which has taken another plural noun like trainers.com.
I was unsuccessful with my applications for these names for .biz, .info and recently .eu because of their trademarks even though the nouns have absolutely nothing to do with their business.
It would be like me setting-up a business with a trademark like Dollar or sweatshirt!
The strange thing is that I managed to register several trade widget nouns in .biz, .info and .eu including for example, stilettoes, boots, sneakers, brogues, sandals, clogs etc as a complete matching set.
The other two noun names I simply bought as ishoes.biz etc.