You are certainly correct. For anyone that saw what happened with the NNNNN.com buyout in 2008, this was crystal clear. NNNNN.com domains were bought out by domainers (myself included) on the hope that prices would rise like they did with LLLL.com's. Almost 20k were registered in a few weeks. While I think that many reasons advanced then for the future value of these domains (namely, rising Chinese internet presence) are still true and even more true today, the fact that they are rare as you say does not instantly give them value. However, a fairly high number of NNNNN.com's are developed sites, mostly Chinese sites, but some are also US and foreign zip code sites, organization/product number sites, blogs, etc. The Chinese keep registering and using these domains, and some of the top Alexa sites are NNNNN.com's and other numerics. So good number sequences to the Chinese can have significant value, as recent sales from 4.cn demonstrate. These may or may not be bought out again. If they are, they may rise in value as an added scarcity premium, but the main driver would be the actual use and demand for the domains in China.