I would say the biggest factor in determining the popularity of a figure is "1-click solutions".  

1. You need a buttload of conforming clothing (and not just slutwear) simply because dynamic is not a 1-click solution.   

2. Tons of pre-made poses (99% of the galleries are just that - who will take the time to actually pose their figure?)

3. Many different characters (dialed morphs and textures), even if they're a rehash of the same old with just different lipstick colours (take a look at what's hot and you see they sell like hotcakes)

4. I'd say a team would need to put all this together and only when EVERYTHING is ready realease the figure.   Otherwise waiting for content will just render the figure useless.

Anastasia is a good example of this.   Many content makers including the OP showed excitement and intentions of producing content and none of this was seen through.   Was she so difficult to model clothes for?   Just a couple of pose packs released?  Even BH didn't come through with all the stuff he showed was already modelled for her (I believe a tank top and shorts and the outfit previewed on DM's pose package along with a great pair of pumps)  At this point even if one awesome outfit comes out I'd have to think about getting it as I can't foresee that I'll be using her with just one outfit. 

I think it's best not to preview anything until a lot of support items are already prepared for the figure.   It's better to overwhelm customers with a plethora of add-ons than to have them wait for six months before they see yet another preview of an outfit that has still to materialize in the marketplace.