The “Facebook-Google duopoly” has crashed funding for advertising technology start-ups to five-year lows, according to reports emerging this morning.  All in all, there were 343 adtech venture deals in 2016 — a 17 percent drop compared with the 414 deals made in 2015. The value of the funding is down too – worth $3.2 billion in 2013, and only $2.2 billion in last year.