Actually, V4 is popular because of V1, V2, and V3. Everybody else's explanations still apply. Victoria's popularity is largely based on the popularity and widespread use of the original Victoria character.

When the first Victoria debuted, it was a much better figure than the P4 female figure. As the Poser program started shifting from its original intent to be a software mannequin to a product used to create artistic renders, there came to be a greater need for more realistic figures. The original Victoria and Michael filled that void. Community support for Poser content shifted from the less realistic figures that came with Poser 4 to the DAZ figures. The companies owning Poser in those early years didn't challenge that new secondary market for selling Poser content and have not been able to get it back now that they want to be in it.

There is currently a momentum behind the DAZ figures that's hard for new figures to break into. It doesn't mean it can never happen, but DAZ has done a good job of not losing that ground. DAZ did learn lessons from the meager support for the first Aiko and Stephanie and now introduce new figures with loads of available content when they first come out.

The main reason V4 is popular is because of the past popularity of the earlier figures. Customers know that the DAZ line of figures will be fully supported by the company and by the community. It's a sure bet that V5 will be the most successful figure when it is introduced. It will have little to do with how much better that new figure is from V4 or other figures.

Let's not forget that the community buys into the new Victoria and other DAZ figures. People, that could just as easily use V3 in their images, use V4. They repurchase all the clothing, textures, and poses, that they already have with V3. We live in a society that loves change solely for the sake of change. There isn't always a practical reason for those changes.

My visual indexes of Poser content are at http://www.sharecg.com/pf/rgagnon