I was extremely happy with this purchase.
Anyone who wishes to uses caravans or trade routes in a historical or fantasy game should pick this up. I especially liked the long listing of different cargoes and trade goods--some of them never would have occured to me, but definitely give a level of detail that would otherwise be missing.
Their fantasy alternatives to trade routes were also excellent! It has inspired not only several plots for an upcoming campaign, but has also caused me to re-evaluate several maps I had drawn based on trade considerations.
XRP's books seem to always be top-notch, and there's no exception here!
A Magical Society: Silk Road