An acquaintance of mine is real excited about this site, liking the idea of the SCP but sick of the bad contributions, so he's showing it off to people, getting them interested in reading and contributing, et cetera. And the idea of a company selling Things Man Was Not Meant To Know Or Fuck Around With to the decadently rich is a good one, and there are some goons out there whoa re excellent at writing this kind of fiction. I just think the site can't work, long-term, if it's supposed to be MCD's catalog.
Think of this: The SCP's entries are supposed to be research entries describing what an artifact/phenomenon is, and how to contain it. The "authorial voice" is a dry scientific one, that has an interest in learning everything possible about the artifact (in order to better deal with it) and conveying that information to the reader. The information withheld from the reader is either stuff the researcher cannot figure out, or things that are too important for the reader to know that end up as [DATA EXPUNGED], a technique the writer can use to keep key details mysterious while fleshing out everything around them. The style and theme is, on the whole, unobtrusive unless the author wishes otherwise.
MCD entries, as a "catalog", can't be written like that. Someone trying to sell an object to you explicitly has no interest in learning and conveying everything about it to the reader; horrible negative effects need to be glossed over or omitted, or it doesn't seem like a sales pitch. The style of "sales" is by definition obtrusive. And for short horror stories, the horrible negative effects are usually going to be the most interesting part; without them you get a record of cool stuff that gets decried as "mary sue bullshit". Yes, you can think of reasons you can get the sales pitch to inadvertently reveal the bad shit, masking it with advertising doublespeak that takes a moment to figure out what it really means, and that can be funny — but you have to do that for every single catalog entry. "Horrible deleterious effects hidden with doublespeak" can be a good joke a few times, but you have to tell that same joke, in every catalog entry, in order to actually convey the information you want to convey. Hiding all the bad stuff behind a "staff only" collapsing spoiler is at least not repeating the same joke, but it's still no solution. It's still an awkward constraint on writing that limits where and in how much depth you can write about Bad Shit, the ancillary details you can include, as well as throwing off the pacing of an article entirely. The same problem remains: writing articles as sales pitches, or sales pitches with staff notes, involves writing them from a perspective that wants to deny the reader some of the most interesting information, and that limitation has to be continually worked around for little long-term benefit.
Instead of the catalog, I believe the same ideas could be emphasized without the awkward constraints if the "MCD" site were framed as an archive: a record for MCD's marketing and HR departments of their procurement agents's correspondence with the company. Letters, telegrams, call transcripts, e-mails, etc, of field agents finding bizarre artifacts and talking to their home office about "Okay, here's this weird thing, here's how I think it works, how do we sell this?" It keeps the central theme of "selling shit man wasn't meant to mess with", but allows a lot more freedom in writing entries. Authors can go into far, far more detail than the "catalog entry / brief staff notes" format allows them if they want: you can keep a terse description of the sellable aspects if you want, or you can give us long and overwrought missives from sepia-toned moustachioed gentlemen of the trials and travails they faced tracking this valuable object down in Blackest Congo in 1860, or give us an agent in the mid-1990s trying to force a description of unspeakable horror into a corporatespeak TPS-report, or a whole host of other styles and periods you could emulate, all while retaining the conceit of "cosmic horror and capitalism".
In this model, authors can keep the sales-copy in their entries if they want, but framing the entries as correspondence rather than a sales catalog allows them to START with the horrible bloody details and then give us the ad-speak sales pitch in the response from home, which puts the punchline at the end where it belongs. Authors of entries can tell stories with as much or as little detail to the narrative as they like, in a number of different styles, while still keeping the overall "voice" and focus of the site distinct. I just think, if the site remains a "catalog", it's just going to be too difficult to stick to the limitations that it requires over a large number of interesting articles.