Sadly, I don't own anything valuable enough to require having furniture with secret compartments. But 19th-Century French aristocrats apparently had tons of stuff that needed hiding, as evidenced by the rash of "mechanical desks" built by famed cabinetmakers of the era. This one here has a rather neat trick, a sort of dual-action drawer. We've cued it up to the relevant part:
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That desk was created by Alfred Emmanuel Louis Beurdeley, a Paris-based ebeniste whose work spanned the 19th and 20th Centuries. Within this realm, we've seen so much of the Roentgen's stuff (here and here, for instance) that I was almost surprised this piece wasn't theirs. In any case, if you watch the video closely you can see, alongside the brilliance of the concept, some of the structural flaws within the design: As the demonstrator closes various compartments with the necessary force, the entire piece wobbles under the wracking forces.
The desk is of course constructed from wood, and absent modern-day fasteners. I wonder if a similar design constructed with more modern materials and joinery could provide the same functionality but with a more robust construction.
As for the market, it seems obvious. We might not live in a society where guys named Jean-Pierre need to hide love letters from inquisitive spouses, but we do have a country filled with plenty of gun owners. With America unable to agree on if they ought be regulated or not, sales tend to rise after mass shootings, as buyers are keen to stock up in case future legislation makes it difficult. It stands to reason that industries producing furniture with hidden compartments will also see attendant sales spikes.