The Tripti Mitra starrer Bohurupeeplay ‘Aparajita’ had a catchline: “It’s not the era of science, rather it’s an era of advertisement.” (“Eta bijnaner yug noy,bijnaponer yug.”) However, today’s world of advertisement is perhaps afflicted with science in an inseparable manner, both in strategy and assessment of business, as well as on consumers’ lifestyles.

Even the classic literatures go on continuing to probe the relationship between advertisements and success. More than a century ago, a fictional mass marketing scenario was depicted by H.G. Wells in Tono-Bungay (1909), where George, the narrator, is persuaded to help develop the business of selling Tono-Bungay, a medicine created by his ambitious uncle Edward. Later a seriocomic study of the stand-off between poetry and advertising is found in the George Orwell novel Keep the Aspidistra Flying (1936). The quest continues. A probe of the impact of promotion on perception is available in Margaret Atwood’s The Edible Woman (1969).

In her book Advertising Fictions: Literature, Advertisement, and Social Reading (1988), Jennifer A. Wicke even mentions advertising as a “powerful mode of social reading”. She also thinks that advertising is “a language in its own right”, which is not “divorced from other cultural productions”. But, how much do such advertisements influence business as well as our daily lives? And, more importantly, do we really need to redefine the style and impact of advertisements, specially with the surge of online and digital marketing in today’s world?

“Nothing except the mint can make money without advertising.” This is how the nineteenth-century British historian and politician Thomas Macaulay felt. According to eMarketer, total media spends on ads in the US in 2017 was $206 billion. Advertising expenditure in India was of Rs. 61,263 crore in 2017, and according to a forecast by GroupM, it is expected to grow at 13 per cent to touch Rs. 69,346 crore in 2018. Ad spending in 2018 will be driven by fastmoving consumer goods, auto, telecom, e-commerce, along with political parties as the 2019 Lok Sabha election is approaching.

What’s the effect of such huge spending on business? How does the return of investment vary, and how is that measured? Does the current advertising impact short-run demand, or simply cause future sales? These are bound to be important concerns of business organizations, ad agencies and social scientists. However, these are not so- easy to answer, and quite often there might be serious errors in measuring the ad-effects, as influences of various other variables get confounded within the responses.

The standard analytics might fail to separate them out. Several kinds of regression and time-series models are employed for data analyses, where the trend and seasonal effects may also be considered. These models study the informative and persuasive roles of advertising, providing insight into the mechanism by which advertising differentially affects various customer subsets. Sales are usually treated as a dependent variable and advertisement expenditure is considered to be independent.

What is the immediate hazard of so much spending on the target people? Certainly, we have to encounter tens of hundreds of ads on billboards, newspapers, TV, social-media, online, mobile, and in-store promotions. In 2015, Digital Marketing experts have estimated that most Americans are exposed to around 4,000 to 10,000 advertisements each day. According to a finding of the market research firm Yankelovich Partners in 2004, this number was 500 in the 1970s.

The New York Times, in 2007, reported the study of Yankelovich, which estimated that a person living in a city 30 years ago used to see up to 2,000 ads per day, which went up to 5,000. Keeping the tech-savvy Indians in mind, this number should not be too less in this country also, on an average. Apparently, it sounds a bit exaggerated, of course. Certainly no one can really process that many ads.

Assuming that we stay awake for 16 hours (57,600 seconds) per day, in order to see 5,000 ads, we have only 11 and half seconds for each ad, even if we have no other activity at all. But, how many of them are felt by our brains? Although about 11 million bits of data per second are perceived by the 5 sense organs (about 10 million bits through eyes, 1 million bits through skin, only 100,000 bits each through ears and smell, and a meagre 1,000 bits through taste), an average person’s working memory can handle a maximum of 40-50 bits per second only, and the remaining data is just ignored.

That’s our capacity. (‘Bit’ is the short form of ‘binary digit’, and has a single binary value, either 0 or 1.) Just to give an idea, nearly 4.7 bits are needed to represent one single English alphabet, say ‘A’ or ‘Z’. And thus, the brain can feel at most 300-400 ads per day, considering the average number of bits needed to feel an ad.

And, making it worse, as psychologist George Miller argued in his research paper in 1956, our short-term memory can only store between five and nine pieces of information. Long-term memory has a greater capacity, but it is unclear what the limit is.

So, we might like to feel some really useful ads among those few hundreds of our capacity. And the fight of the multi-billion dollar advertising world may grab just 50 bits of our sense, at most.

The writer is Professor of Statistics at the Indian Statistical Institute, Kolkata.