To understand 'brandables' more,
a) If it is just (purely) invented one, the end user is going to try his best to 'invent' one himself - and I am sure there are plenty still available. But the con of these is I would not expect a user to reach me for the invented brandables of his own (through type-in or whois) . Another con of these is that it 'costs' lot of money for a business to brand them. If you look at the brandables we come across daily - most of the pharmaceutical products, how many of these we actually remember? But the pros of these is that they are generic and they can apply to many niches/domains/industries - so they have much more applicability, hence more marketability from sellers' perspective.
b) For Keyword brandables, challenge is there but less. The user can search by keywords but the challenge again is - would end user think of the word(s) you have besides keyword. They have limited (industry) scope but more appealing to customers and can qualify as 'niche' domains. Because they immediately signify what you do/provide. It costs much less to market them - they are definitely catchy and easy to remember compared than purely invented ones or even generic words names.
Either way, it is very hard or rather impossible for the end user to reach the seller for the brandables through whois or type-in - human mind just does not work that way. Searching for them on a listing site is equally hard, because even if you categorize them, it is not that effective, as 80% of the name probably fit into about 80% of the categories. For these reasons, turnover of brandables is much less compared to non-brandables (generic words if I may say). Brandables have many many alternatives compared to generic words names. It is really a hit or miss with brandables. For generic word names, there are limited synonyms/related words, and by swapping the words - you just lose the intrinsic meaning you were looking for in first place.
There are some more considerations
1) Number of users have hundreds of brandables, even if they sell 2-3 names in a year, they recover cost of 500+ names. So it works for them. But the challenge comes for newcomers who have names in 50's or less, without a sale, they will not be able to break even. I would assume smart domainers would keep a mixture of names, brandables/non-brandables/generic names so that they have cash flow going. "Just like a smart stock investor would do".
2) There are tons and tons of brandables around, besides searching, and bigger issue is that another brandable looks better or at least comparable to what you have just seen - how many pages of brandables one can flip through. Keywords - you think of 3, 4 or possibly 10 max and that is it. So it is very tough for a buyer to chose one brandable over other. Is it matter of liking or pricing. I would assume former to be the case, if the prices are comparable, which is true for 80% of the brandables.
3) People should really give it a serious thought - does a business(end user) really need a brandable? It really does not have to be TM, it can be SM or can be marked as some way. Even a fair use of a name can quality a name to be TM/SM'd or preventing others from doing the same. Keep in mind - for service related names, what matters is the underlying technology/process and not the name itself, while for products, purely invented names do well. So it largely depends on whether you are selling a name for a service or a product.
I have given some considerations, not to draw to any conclusions, and hope it is helpful to readers and allows them to think harder about their strategy.
