The September peak is specifically for online apparel shopping. The trend is predictable and has been happening for a few years now. "We believe this second wave in apparel purchases reflects in part students responding to the new trends they're observing at school," said Lynne Laube, the president and co-founder of Cardlytics. Laube also described changing search queries in Google and that their hypothesis was validated by advertisers. "Intuitively, this effect makes sense if you consider how sensitive students are to their peers."
The problem for retailers is the second peak only exists online, not in stores. "Parents are too busy to visit multiple stores as they had before school began," said Laube. Also more importantly, they've gotten the information they need. "Parents are more familiar with apparel sizing and thus more confident to buy online."
If retailers know this is going to happen, shouldn't they be doing something about it, rather than losing all those sales to online purchases? "Retailers should drive awareness of their e-commerce site among in-store customers," said Laube, "and highlight convenience factors like free shipping, easy in-store returns, and larger inventories." Finally, Laube also advised retailers to "extend Back to School ads and promotions online to capture shoppers who are shopping online longer."