Sharing 3d art in ArtStation

For me no it didn't have any effect (artstation).

I suppose it depends on the category of things you sell or what people need. Any social/art platform will give you increased exposure, however I would think of it from the artist perspective - do I want to see furniture models for sale, probably not unless that specific item was something my clients are asking for. You can think back to items like Pampas plants, Monstera - these things sold like hot cakes.

Look at what people are doing on artstation - you can sort by best selling or whatever and you will notice that people on that platform want good anatomy reference, brushes for zbrush/substance/etc, kitbash collections for concepting in 3D... Basically every site has their niche and when you spend some time researching each one you will see if it can benefit you. Twitter is great for plugin/scripting devs who want to show what they are working on as it gives people a window into why their product is useful to them. Instagram is good for showcasing animations or keeping a simple history of visual work that you do - if its creative and interesting people may offer you to work on their projects or 9/10 try to scam you with some instant followers lol. Just do your research basically, try things you might be surprised with the results or not, but at least you know as long as you track where your traffic is coming from.

Have you tried Pintrest to increase your exposure? Not sure if its a coincidence and its to do with the time of year but my sales have increased since posting stuff there. Try it it costs nothing!

In general, Artstation Marketplace is site for vending tools, materials (especially Substance Designer), reference photos, Marvelous Designer costumes and basemesh collections that 3d model-builders and game makers use in their work. It is not a good place for general types of 3d models, especially those that architects might use. The best selling models sold on Artstation are those useful for games. I don't believe architects and interior designers tend to visit Artstation on a regular basis.

Can increase, in theory. In practice you will have to spend a lot of time to attract stable subscribers and buyers.
You can also try Behance. There is more CGSociety but this platform is taken over by spammers.