I have checked the list of NNNNN.com domains. still little avilable. also checked NN-N, N-NN Domains & got the same answer. Also i have seen some good iNNN.com Domains. Are they Good To Invest?
Personally, I wouldn't touch NN-N.com, although some people think it's the next craze since all the N-N-N.com & L-L-L.com have been bought out. As to NNNNN.com, unless it's a US post code, which would've been bought out already, or a repeat number, like 10000.com, etc, I wouldn't just jump in to buy them. If it's something random like 01529.com, I wouldn't touch it, but that's just me