can you please tell me what letters I shd look into (or) focus on while finding 3LETTER DOMAINS in Expired Domains list of popular extensions like .CO, .IO, .ORG, .NET, etc? [
I think this is where the market has no idea or registration value. The advantage of gtld is you can have two dot words. With 3L + 3L extension all you have is the power of the first 3 letters of the abbreviation and rely on the strength of extension. eg abc.xyz may have some value where tys.xyz may still be available in dot net and dot org. It is a two horse race dot org and dot net.
LLL.net has some low and high sales history.
Best performing letters are: A, S, E, M, D, I, T, O.
Other strong letters include F, G, H.
The letters J,K,Q,U,V,W,X,Y,Z are referred as non-premium letters.
Q, X, Z are the weakest.