The research group predicted in a study that social media data collection would soon move from largely reactive "listening" to a proactive gathering of insight.
Such a shift is especially vital as Millward Brown's assessment of 30m online conversations found as few as 40% of brand "mentions" were made by human users.
As such, marketers must consider the role of "spambots" when monitoring buzz and influence. Enhanced transparency and sentiment analysis, as well as employing more rigorous research methods, are similarly key.
It was also stated that 2013 should herald the arrival of "bigger, bolder, more interactive - and intrusive" ads on Facebook, the social network. These include more sponsored stories and video ads in users' newsfeeds, and expandable and richer formats.
"Brands will need to tread carefully as they explore these new opportunities. Some users will tolerate prominent advertising in return for free access to their friends and social connections, but others may balk at increased commercialisation," the study said.
In keeping with this trend, "omnichannel marketing", where campaigns crossing the web, mobile and offline media are set to gain ground. Combining social networks, mobile and in-store data are just one example of this process in action.
"A retail brand might look to integrate loyalty data with social applications to deliver relevant offers or messages to consumers when they're in or around store locations," the study said.
Turning to mobile, Africa was predicted to yield vital insights for firms seeking to leverage wireless devices, as the number of mobile phone users in the region grows towards the 1bn mark in 2015.
As the majority of the continent's web audience still go online from a mobile phone rather than a computer, it should "epitomise the post-PC era", demanding bespoke solutions covering everying from feature-phone tools to smartphone apps.
More specifically, Millward Brown asserted that these gadgets will increasingly become "mobile remotes", or a "brain" storing files, pictures, music and video, and controlling other appliances around the home.
For their part, media owners are expected to make greater use of social TV, where members of sites like Twitter actively engage with shows as they are broadcast or between episodes. Paywalls should also grow in popularity for content providers.
In tapping all of these trends, real-time planning - where brands can generate insights and tweak campaigns as they run - is likely to become an "essential feature" of the landscape. Warc subscribers can access a series of Admap articles discussing this matter here.
Data sourced from Millward Brown; additional content by Warc staff