Amazon & The Duopoly: Is Amazon the only force that can take on the digital ad duopoly of Google and Facebook? Forrester Research estimates that Amazon will generate $2.5 billion in ad revenues by 2021. The forecast also predicts that in-app video ads will drive growth in overall mobile advertising over the next five years.

Amazon Pt. II: (Content behind paywall) Evidently, media execs are also bullish on Amazon's digital advertising prospects. A new survey from Digiday found that 90% of that group believe the ecommerce giant has the means and inclination to take down the duopoly.

Mobile Trade-Ins: Time to upgrade that smartphone? Holiday shoppers seemed to think so. Phobio reports that trade-in volumes for smartphones spiked by 57.1% this Black Friday and by 30.2% on Cyber Monday, indicating consumers are looking to upgrade their devices. That process is being aided by the fact that trade-in values for the devices have increased by almost 60% over the past five years.

Wearable Bulls: Worldwide shipments of wearable devices hit a new high of 26.3 million units in Q3 2017, according to International Data Corporation (IDC). That was a 7.3% increase from last year. Fitbit and Xiaomi led manufacturers in shipments for the quarter. But IDC noted that retailers like Fossil and Movado were increasingly blurring the divide between tech-focused wearables and fashion.

Instagram Corners Businesses: Instagram now boasts 25 million businesses on its platform, the majority of which it says are small businesses. The visually focused social platform reports having 800 million monthly active users overall.