Using an authority hub, it can allow anyone to specialize in a number of niches all using a single page site. It is not hard then to imagine this when dominating your favorite niche. The theory: division of labor increases profitability. If one wants to specialize via niches, advertising becomes more valuable, because the target audience can be reached more efficiently.
This hub and spoke strategy theory is microcosm: the hub is the well-known authority, the spokes allows for relevant niches. We used to celebrate if we made the front page of Google, but that's not enough anymore; you have to dominate it. I believe this will do it.
Yesteryear we liked to set up a website and work it day and night to perfect everything about it. We change the content with new and informative information, then rinse and repeat with a new website. Today we can go further; over the top, outside the box, the sky is the limit. Are you going to be left behind?
I am familiar with the "Hub and Spoke" system, and if done correctly it could work very well.
One small tip though... Make sure your sub-domains (at the end of each spoke) are inter-connected with links to each other, and that each sub-domain is also linked back to your main domain (the Hub)
Hope it makes sense to you.
-Theuns