As I've been told, OOO medals sold like hotcakes and nothing has sold better since. No idea about before then, though.

I can only find information up through 2011, but it looks like Ryuki had the most successful toyline, raking in 13.9 million yen that year. Hibiki predictably had the lowest sales at that point, but I've heard that both Wizard and Drive did really badly in sales.

Ryuki had the best toy sales before Decade from what I've been told. I hear Hibiki had poor toy sales during the first half of the show.

Drive was, as far as I know, the worst-selling toyline since Kiva, meaning it hat lower sales than even Wizard. The best in the last few years was indeed OOO.
However, considering how many variations of Figuarts we get from Tamashii Nations, the show seems at least to be popular with merch for adults aka everything that's not in the main toyline.

That's basically why Ghost shoves so much merch down our throats.

If we get them. Anything beyond KR Chaser is not confirmed for a release yet, not even Type Tridoron and that is the final form of the protagonist.

And I don't know if the SHF's really did well, from the 5 retail released figures I can find 3 still in stock over at HLJ which is a pretty bad sign, and everything else was Web-Exclusive anyways.

I think we can’t really see if Drive was popular with adult collectors just from this, Tamashii might tell us when we see which of the shown prototypes from the event actually see release.

... SiC Fourze damn it.

Online, yes. But getting them in stores in japan right now is much more difficult. Especially Merchandise relating to Mach and Chaser is out of stock at a lot of places or the prices skyrocketed.

And this is what I was referring to, because the Japanese fans are those that Bandai counts in. HLJ is a page that is mostly used by people out of Japan.
But getting SHF Mach IN Japan was pretty much a struggle. I didn't find a single one in the shops on Akihabara's main street and ONE of three local toy stores here in Shizuoka had like two or three of which I bought one. Mashin Chaser is a tad bit easier to find, but also pretty rare. Also Drive Type Speed- I've seen some Wild and Technique here and there and they kinda throw Dead Heat at you, but Type Speed... I think they had like one at Mandarake during the week I was there and someone bought it while I was at the store for the first time and they didn't get a restock during that week.

Which is what makes me think they didn't just announce tons of Drive S.H.F., but we will probably also get lots of them (which makes me even more disappointed they didn't announce Medic).

Drive figuarts didn't seem to sell out on the same rate as the Gaim ones did from what I can remember. Type Wild and Type Deadheat still seem easy to fine while Kachidoki sold out really fast IIRC.

Well, Deadheat and Kachidoki are not the best point to compare the lines though, as Formula would be the Drive equivalent to Kachidoki- also, Drive Type Deadheat was rarely used on the show itself, the form is more associated with Mach, so no wonder the Drive version doesn't have the best sales.
As for the Gaim ones, I can't say how well they sold in the shops as I have only witnessed the end of Drive in Japan, but it is a fact that Gaim was very popular with the adult fanbase, so we can assume the S.H.F. were selling well.
Which doesn't change anything about the point that the Drive S.H.F. have pretty solid sales as it seems and seem to be far more popular than the main toyline- my original argument had nothing to do with any other shows in the first place but was solely referring to the Drive sales alone, so I don't quite get why you brought Gaim up.