Amanda Holding, left, and Sierra Gillespie, both of Lawrence, balance their shopping finds at Kohl's, 3240 S. Iowa St., as shoppers were out in droves on Thanksgiving Day.

Marketing concepts like scarcity — Limited time only! — and social proof — Everybody’s doing it! — made Black Friday the frenzied shopping phenomenon that it is, consumer experts say.

But with all that popularity, is Black Friday’s bubble about to burst?

From a marketing angle, maybe, experts from Kansas University’s School of Business say. Those tempting day-after-Thanksgiving sales seem to bleed out more every year.

Noelle Nelson, an assistant professor in marketing, points to the one-uppers and the piggybackers.

“They’re opening earlier and earlier, until earlier became the day before,” she said.

“Already it’s losing its potency. It’s not going to be this buying frenzy that they’ve had — people are not going to get this sense of urgency.”

First there was Black Friday.

Now businesses push Thanksgiving Day sales, Small Business Saturday and Cyber Monday specials.

Black Friday “doorbuster” deals have busted into the days and even weeks before. Snippets from this Sunday’s glossy circulars: “Why wait? Beat the rush,” and “Black Wednesday Prices Just Like Black Friday!”

One Kansas City area shopping center advertised Orange Wednesday the day before Thanksgiving this year, proclaiming: “Orange is the new Black Friday.”

Nelson said she’s even seen advertisements guaranteeing Black Friday prices all the way into January.

There’s not great evidence to prove these are the best prices of the year, Nelson said, but people do perceive they’re getting a really good deal.

Jessica Li, an assistant professor of marketing who specializes in consumer behavior, said social proof and scarcity are powerful tools.

She described social proof as the idea that we want to do things that other people do. After all, she points out, getting up at 4 a.m. and waiting in the cold outside Best Buy would seem pretty silly if you were the only one there.

The concept of scarcity makes consumers feel like they need to move quickly so they don’t miss out, she said. “That creates a sense of urgency.”

Li said overdoing it could eventually water down Black Friday’s effectiveness, though a lot of businesses may not realize that.

“What they’re thinking right now is, ‘How do I get a piece of the action?'” she said. “They’re not thinking long-term.”

But let’s say ads do wear off and that sense of urgency goes away. Does that mean Black Friday is a total bust?

Doubtful, Nelson and Li said. Partly because now there’s a strong social tool besides marketing in play: tradition.

For many, Black Friday shopping has become a social ritual, Nelson said. Those families and friends aren’t just looking to check gifts off the list or buy things at deep discounts.

“At this point for a lot of people, it’s entertaining,” Nelson said. “It’s about the hunt.”