Yes, content and functionality seem to be the driving forces behind these types of expansion.
However, I did read in Website Magazine
recently that web users generally seem to favour website speed
over functionality. Add too much functionality, and it slows the system down.
Tech designers know that you've gotta keep the users happy, so it presents them with a stimulating challenge, to find ways to build faster systems. Challenge drives innovation.
The new face of Twitter is going to be very interesting, indeed. It's getting hard to keep up to all the tech changes across the Internet as the Information Age accelerates!