Ah ok, I checked that thread and honestly there's some very good information there already. I completely agree that the structural and efficiency difference in Xenforo is a noticeable change coming from vBulletin, along with UI and user navigation experience. The nature of how Xenforo pulls users throughout the site can have a direct impact. But as someone stated, this isn't necessary a bad thing. As Jeremy stated, the use of overlays alone plays a part.
If you're speaking revenue here, you could theoretically disable overlays if you're running ads everywhere, and inflate the pages viewed to perform basic site functions. But again, is this good user experience?
Also, vBulletin was a very bloated software (albeit can depend on systems used along with it, such as mods) and could easily inflate metrics in a useless way.
I'd say firstly, is there a revenue drop corresponding to the lack of page views, and importantly, less page view time and increased bounce rate. That could signal something else entirely.
You're also going to go through some havoc in some metrics changing over software by pure principle. Over time though, many large boards recover and actually increase performance with XF over vBulletin.
