Makes them not come off as a fad or BS scheme to get a VC exit on a non-product, yeah? Interesting traits. I hadn't noticed it until you pointed it out and then... what you said might be why I hadn't noticed them lol. I'll add that a tech company operating in stealth or low-buzz mode has the extra advantage of building up quite an income stream before competitors' marketing or legal teams notice. That money helps when either responds to the new threat to their market share.

Some of the best companies I ran into in robust, software engineering are still unknowns. You don't see them or their methods on HN, Reddit, and so on. Yet, they continue to slowly grow and be profitable by word-of-mouth as they deliver results day in and day out. Nothing wrong with advertising but I admire those companies the most.