It's actually a lot worse than I thought. All the things mentioned are valid. Daz3D is a much easier store to buy from. But I spoke with a content creator who works for me and she brought up some other, much more significant hurdles. The impetus of all this was me wanting to purchase some hair I saw on Daz3D. There was NOTHING like it on Reallusion. Nothing even close. And the artist who made it has done a TON of other stuff - including lots of great hairstyles. So that's when I decided to go on my 'mission'. Then I spoke to my artist and she explained it won't happen for these reasons:
1) The hair on Daz has a lot more options because of the Daz system. Apparently hair in Reallusion deforms and flows in weird ways, whereas on Daz the hair moves more naturally. Also the hair can be 500K poly without an issue because dforce can use hair made of fibermesh. I didn't know anything about that, but I do know there's WAY more hairstyles on Daz - and lots of very LONG hair. It looks amazing.
2) A vendor can do FAR more business on Daz than Reallusion. Now she might've been exaggerating, but she said a vendor could bank a $1000 in a week (presumably on a single item), and it would take a year to make that on Reallusion. So the investment isn't worth it.

Then there are all the reasons mentioned on this thread. So what ends up happening (WAY too often) is Reallusion people just buy their stuff off Daz and convert it so it works in Reallusion. To me that's Reallusion kind of giving up. Why not attract those content creators to come and sell on your store?? They sell everywhere else (most vendors who sell on Daz also put their items up for sale in other stores, like Renderosity), why not here? And it's a real problem, to the point where I was questioning whether or not I made the right decision in choosing Reallusion. They should be trying to ATTRACT top talent. Give them incentives to come and innovate. But, at the end of the day, Reallusion is a better fit for ME. And, I will continue to really support the top vendors who sell on Marketplace and just try to convince them to make what I want with a little extra financial incentive if necessary. That's basically all I can do, unless Reallusion hires me. But yeah, more than just the store needs an overhaul. Great product though, I still prefer it over Daz.

This right here.
I would have bought from Marketplace many times if not for this weirdness. 

It isn't that simple. Some of it is a dislike for the way the marketplace is run where you are given points instead of being paid in currency. You can convert the points to currency as I understand, but it's an unnecessary step which turns off a lot of buyers as well. Instead of just buying the item, they have to go to Reallusion and buy points in order to purchase the item they want. Reallusion doesn't seem to think it's a problem --though it's been a point of contention in the forum for years. Not to mention that the way the marketplace is set up, it's not easy for people to find what they are after without a lot of extra searching. DAZ is much more adept at storefront design and it shows in the amount of traffic they receive. It's pretty sad that when you click on content items in the marketplace and on the main content store, you may be taken back to the Reallusion Iclone 4/5 marketplace which looks hopelessly outdated and there are a lot of broken links for pictures and some video you can't watch because it was made in flash or is no longer linked properly. They're improving slowly but they really should sit down and think about how users look for things that they want and properly catalog their items so they are easy to find. All and all I say the marketplace itself is in need of an extensive overhaul. If you want to attract content creators, you really need an attractive storefront. No one wants to sell their items on an unappealing front end experience.  

Reallusion Marketplace is great, but every time I go to Daz3D I just see way MORE stuff - and it happens to be stuff I want to buy. I don't buy it because it can often import into CC4 without all of the functionality - especially when it comes to hair. So, in 2023 I've made it my resolution to 'recruit' top content developers to put their products on Marketplace. I'm trying to determine what hurdles are in my path and (most importantly) how much they cost. Am I correct in assuming that content creators need to OWN a copy of CC4? And, if 'yes', if I purchase their copy can they use it on their computer?? Or can I just add on to my license? I don't want to break any rules or anything, but it's significantly cheaper for me to buy it for them because I have discounts and I pay the upgrade cost. I need to remove as many barriers to entry as possible for new content creators. And I treat these people like a sports team owner treats talented players. I will woo them to Reallusion if I have to.