Many businesses are now well-versed in the COVID-19 consequences: Low offline sales, flexible work from anywhere options, fluctuating foot-traffic with lockdown mandates, and ecommerce becoming a channel that many brands wish they had created infrastructure earlier.Advertising dollars are flowing in as a record number consumers in Southeast Asia shift from shopping malls to online platforms such as Shopee, Lazada and Tiki. Retail media is now a common feature in emerging markets.Amazon Advertising, the first marketplace that offers bid-and-buy, was the catalyst for change in North America in 2018. BCG estimates that retailers have a $100-billion business opportunity, if they keep up with the pace.The money is where consumers areIt is important to understand the modern marketing landscape in order to understand why retailers are more likely to spend on advertising.Are they bus stop ads? Bidding on Google keywords, or a Clubhouse session Is it a viral TikTok clip? Modern marketing is a mixture of all channels that are tied to key performance metrics as the world becomes increasingly connected.Marketing, regardless of medium, has the main purpose to promote a product or business to the right people to make a sale. There are many ways to do things.E-commerce is a unique advertising channel because it encompasses the entire consumer journey, from start to finish. This is especially true as search engines continue to dominate the market for search engine results.Because these mediums were popular at the time, traditional marketing channels consisted primarily of linear TV, radio, and print. With the advent of the internet, newer platforms like email, streaming, and websites emerged. Then, came social media and apps which revolutionized the advertising industry. Regardless of these changes, one thing has remained constant: the business went where consumers were.When revenue and traffic sources change, let's say because of a pandemic or other reasons, the marketing mix will follow. According to Nielsen, marketers will decrease their spending on cinema, print, and out-of-home (OOH) over the next twelve months. However, the majority of marketers will increase their budgets for social media and search.Search for the best advertising channelsWhich channels will be able to benefit from money flowing out of old buckets? Trends in ad revenue in mature markets such as the U.S. are a good indicator. Although Facebook and Google remain the most dominant advertising players in the U.S. market, Amazon has risen to the top of the duopoly's ad revenue pie, increasing its share from 7.8% in 2020 to 10.3% in 2020, according to eMarketer.How do you know? The most effective advertising channel is one that can be measured with consumers.