A. The digital marketing industry in the USA is estimated to be worth $19.8 billion (by way of revenues) as of 2021. The handsome market size has naturally been driven by countless digital marketing agencies and brands in the USA. As per estimates, by the beginning of 2021, there were around 5,523 digital advertising/marketing agencies in the country. This figure reportedly increased by 13.7% in comparison to the year 2020.