Charlotte Mceleny looks at the 11:11, or Singles Day, shopping phenomenon, and the impact of ad tech on proceedings…

Next Wednesday (11 November), shoppers across Southeast Asia will head to Shopee, Lazada, and TikTok Shop for the year's biggest discounts, as they do every year. Brands will follow them with their budgets, and when every advertiser bids for the same shoppers in the same few places on the same day, the price of being seen goes up while the question of what that money buys gets harder to answer.

Flywheel's analysis suggests it buys less than most dashboards show. Kshitij Pradeep, head of e-commerce at Flywheel Malaysia, puts the incremental share of the 11.11 sales uplift at around 15–20%.

"The rest is largely demand that would have happened anyway. Shoppers delay purchases in the weeks before to wait for the sale, or bring forward purchases they would have made in December," he explains.

Where costs climb

Brands pay a premium for that uplift, and on the marketplaces it arrives early. Flywheel see total media investment around 11.11 rise by roughly 20% against an average month, with the steepest price rises inside the marketplaces themselves.

"Marketplace media sees the sharpest inflation, with Shopee costs increasing by 17-25%, followed by TikTok at around 15% and Lazada at 10-15%. The escalation begins well before 11 November itself. In most categories, pricing starts to climb from 1-3 November as brands ramp up pre-sale activity and audience acquisition efforts," says Pradeep.

He adds that prices stay high through the post-sale retargeting window and only settle after 13 November.

"For advertisers, this means the effective 11.11 cost window extends nearly two weeks, making early planning and budget allocation critical to maintaining efficiency during one of the most competitive periods of the year."

Away from the marketplaces, the spike is harder to find. Penelope Siraj, senior partner, media and marketing strategy at Brainlabs, says her team can't isolate a double-day effect in biddable channels at all, because 11.11 sits on top of the wider year-end rise driven by Christmas shopping and, for travel and ANZ campaigns, seasonal demand.

"We are not really able to pinpoint a 11.11-specific or double-day-specific increase in biddable channels; what we see more of is that some audiences' CPM costs increase as more brands are bidding for them and competing for the seasonal campaigns," she says.

What happens outside the marketplaces

Pradeep sees open web and CTV activity fall away during the double-day window as both shoppers and budgets move onto the marketplaces.

"Consumers in Southeast Asia go straight to Shopee, Lazada, and TikTok Shop to hunt for deals, and brands follow that traffic with their spend. Off-marketplace channels lose much of their relevance for those few weeks."

Nor does he see the marketplace scramble leaving cheap inventory elsewhere, at least during the peak.

"We don't see a pocket of undervalued inventory that brands are overlooking during the peak. The bigger opportunity is over the next 6 to 12 months. New channels will start to take share from the established marketplaces, and TikTok Shop shows how quickly this can happen," says Pradeep.

Brainlabs haven't seen off-marketplace prices move either. Siraj notes that brands selling physical products tend to run their double-day promotions through DTC and retail media sites, and fewer clients selling non-tangible products feel any urgency to take part.

"In spite of what seems like increased competitive pressure, we have not observed a specific increase in open web or CTV costs; for our audiences, there is still inventory available, and we tend to rely on PMP deals for CTV to manage costs," she explains.

Building before the sale

Pradeep is blunt about brands that save their firepower for the day itself: "Building audiences ahead of the event is consistently what separates strong 11.11 performance from average results. Heavy spending on the day alone is hard to sustain. Costs are at their highest, every competitor is bidding for the same shoppers, and brands without warm audiences end up paying a premium for cold traffic."

The model Flywheel see working is a phased build towards the sale, using off-site channels to fill the funnel before the marketplaces get expensive.

"In the weeks before, brands scale prospecting through off-site channels such as Meta and Google to drive traffic and grow their audience pools. Those audiences are then retargeted on the day, when purchase intent peaks," Pradeep adds.

Siraj reaches the same conclusion from Brainlabs' wider sale-day data, which extends beyond Southeast Asia's double days to Prime Day.

"Our sale day data evidence points to building early in the run-up instead of only starting on the day itself. This holds also for Prime Day and other shopping days,” she adds.

One season or four sales

Pradeep argues the run of 9.9, 10.10, 11.11, and 12.12 needs its own Q4 budget envelope, with each double-day planned as a distinct event.

"9.9 typically opens the season and is a good moment to recruit new shoppers and test offers. 10.10 builds momentum, 11.11 is the largest event of the year with the highest competition and costs, and 12.12 carries year-end and gifting behaviour. Shopper intent, competitive intensity, and media pricing differ across each one."

Siraj points out that plenty of brands skip 12.12 because it collides with the Christmas season, and Brainlabs' tests favour a single plan where sales run back to back.

"The tests that we have and previous campaigns lean to one flighted programme being more effective where there are consecutive sales like 11.11 and Christmas," she says.

What brands are paying for

All of which brings the conversation back to what 11.11 is for. Pradeep warns that the headline number on the day can hide a flat quarter.

"A spike in GMV on the day can look impressive while overall sales across the quarter stay flat, and margins take a hit from deeper discounting and inflated media costs."

"Advertisers should measure 11.11 against a baseline across the wider period, including the weeks before and after. They should also look at metrics that point to real growth, such as new-to-brand buyers, basket size, and repeat purchase. Those are the customers who make the event worth the premium," he adds.

For brands heading into next Wednesday, Brainlabs and Flywheel point the same way: the budget that works hardest on 11.11 is spent in the weeks before, building audiences while prices are lower so the money on the day goes to shoppers who already know the brand. Whether that runs as one Q4 programme or a series of distinct events depends on who you ask, but Flywheel's incrementality figures make the bigger risk clear, since judging 11.11 on the day's GMV alone means paying peak prices for sales that would have happened anyway.