What do you need to make Marmoset Previews?

If you want to persists you can basically upload to sketchfab and paste the link in the description or capture a video and upload it to youtube and embed that in the uploader.

However, keep in mind sketchfab is not safe. There is software out there that converts the incoming browser file back to original OBJ files, those models are then used as bate for download websites.

Marmoset is probably not immune to this, note that those viewers work by converting 3D files to some proprietary file format, those files get requested/send to the local machine of the user where some script converts it to common webGL your browser understands, so keep in mind your models get uploaded to local machines all over the world and stored in cache on the disc.

This is actually a licensing problem as copy's of your work get distributed before licenses are obtained, so in a sense unauthorized copy's of your work are being made all the time all over the place, even worse, people that have the hack software convert the incoming proprietary file format back to common OBJ format (including textures and UV’s, etc.)

Personally I make screen videos to demo my models, its safer and not contradicting copyright terms.

I'm afraid the PBR features don't really interest me. I make very cartoony, low-poly, game-oriented stuff. It seems like a lot of money for something that I would only use to make the preview file. It's hard to say if I would actually regain the cost from the models I sell.

Marmoset Toolbag (https://marmoset.co/toolbag/) is a real-time PBR rendering software and its great for previewing your scene or objects in real-time and near photo-real, its very easy and fast to setup and you immediately are capable of previewing your PBR materials and determine if somethings need to change. It has lots of render features like real-time ambient occlusion, voxel based global illumination, soft shadowing, reflections/refraction, emissive materials, volume fog, DOF, glow effects, chromatic aberrations, etc. It can also play and render animation and import Alembic files.

You indeed need Marmoset Toolbag software on your machine in order to use the viewer, if you have it then go to export and select Marmoset viewer, this brings up a window showing export options, set the preferences and click export, this outputs a .mview file and you can upload it in the section “embeds” below the preview images in the CGt publisher, click the “add Marmoset preview” window and upload the .mview file, that's it.

I use Marmoset allot and I like it because its so fast and easy to setup and it renders amazing quality instantly. I also use it to play with lighting rigs and have real-time feedback on it before I move to Octane Render.