In the absence of other oversight, a brand name provided a degree of trust - advertising is a form of costly signalling, indicating that the advertiser is investing in their reputation and would have something to lose by selling a shoddy product. The brand of flour I've never heard of is far more likely to be padded out with gypsum or chalk than the brand of flour that has advertised in the newspaper every week for the last four years.

We're seeing the inverse trend today, with sites like Amazon being flooded with white-label products of unknown safety and quality. In many product categories, there just isn't a brand with widespread recognition, or the sheer number of off-brand products has drowned out the branded products. These white-label sellers have little or nothing to lose if they sell a shoddy or outright dangerous product - they just take down the product listing, put up a new listing and buy enough five star reviews to get the ball rolling again.

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