Not that lucrative at this point for sure, though we have reported several four-figure sales of LLN domains at DNJournal this year. There is a big difference between the 3 classes. LLN are easier to sell because that convention is used by thousands of companies when naming products. NNL or NLL are occasionally used that way but far less frequently than LLN (even so, the examples you gave of those above are NOT available for registration - I just checked them. Though not as strong a class most of those also get registered at soon as they drop). LNL or NLN are rarely used and I completely avoid them. Doing a few searches on Google will confirm the usage patterns mentioned. As in all other categories, it pays to stay on top of what the market is doing today - what was happening six months ago is meaningless.