In deep typography circles, 'parametric fonts' means typefaces where their attributes are isolated and can be controlled as parameters.
That can be done with OpenType Variable Fonts (eg Decovar and Amstelvar) but is not commonly done with them (eg OTvar fonts with just Weight and Width axes)
Its more common that parametric fonts are made with 'generative font' formats, like metafont and www.Prototypo.io, where there is a turing complete programming language that controls and generates the letter shapes.
Metafont has never found wide adoption, because to be a triple threat of typeface designer, mathematician, and software developer, you basically have to be a tenured stanford professor or their grad student to have enough time to learn everything well enough to make useful type.
And even then, the typefaces made with metafont are often very poor designs compared to those draw in a GUI in a 'dumbfont' format.
Adobe Multiple Master, then TrueType GX, and now OpenType Variations, are a 'best of both worlds' compromise; the drawing quality of visually crafted outlines, and the continuous-space-type-family-in-1-file typographic flexibility of metafont.
The www.glyphsapp.com and www.fontlab.com font editor apps have "smart components" which do this. Sadly the OpenType format is developed very conservatively by Microsoft so these aren't part of the only widely supported font format today, despite recent additions to the format of run time interpolation technology.
The fonts are made with freshly written extensions to the RoboFont editor; notably, the original source drawings are made in quadratic bezier splines, not the typical cubic ones.
Metapolator (a project I co-founded) uses Hobby splines and has not been used so far to develop Variable Fonts AFAIK.
Rule 1 of advertisement. If your customer can't understand the message while flicking through a magazine, skimming through webpages or driving past a sign nobody will buy your stuff. Most buy desicions are even made unconciously.
I see a lot of artsy advertisement and packaging from people fresh out of school amd that stuff simply wouldn't fly in the real world.
