I have a toy bike taxi on my shelf from when I met Asif and Tareq at WCUS. It's pretty good anecdotal evidence for my agreement with his conclusion that networking — sometimes combined with clever tokens to help folks remember you — is an effective marketing tool.
M Asif Rahman writes about his experience sponsoring WordCamp Europe for weDevs. He analyses the time and actual costs, the value beyond direct sales, and more. He also raises a very valid concern around the timing for WCEU 2018, which conflicts with Eid al-Fitr, a very important holiday for Muslims.