I have several projects, all of them on vB 4 and only because there are blogs and social groups there. Blogs are an integral part of the forum, people create for example a product and they want to create their own discussion in their part of the resource. Many migrate already from social networks and they also need their own part of the forum - it's their part - not the thread of the forum, but part of the resource. Of course you can say blogs are moving away - but see how many people are writing in this topic and want to see the addition of the Blog. And how many forums can not switch to XF 2 because they understand how difficult it will be to deprive users of their blogs - what should they do? Buy third-party, non-integrated solutions? Yes they do, but they are not quality products. Of course development is an expensive activity, but make a Blog for $ 300 - I'll buy it, because I need a quality product. I need social groups, I also buy them for $ 300 - because I need quality solutions from your company integrated into the forum. Make a poll, about blogs and social groups, determine the goals and price of products, I'm sure many will support me, and how many more new users with vB 4 will go to your team when they see such solutions.