Brands should be wary of attaching price tags to the products they pin on Pinterest, a new study from analytics startup Pinreach and Josh Yang, a MBA candidate at Harvard Business School, indicates.

The two parties discovered that pins with price tags are just as likely to be shared as pins without price tags. Both types were repinned between 5.4 and 5.5 times on average. Pins with price tags received slightly more likes, however: 1.4 likes per pin versus 1.1 likes per pin.

Users can attach price tags to pins by typing in a “$” sign followed by one or more numbers in the description box. The price tag appears not only in the description, but also in the upper lefthand corner of the pin thumbnail and image, like so:

The results were based on a randomized sample of 1 million pins, 1.2% of which bore $ tags.

When brands affixed price tags to product pins however, users behaved differently. An analysis of 2,588 pins across three “major ecommerce sites” showed that followers were far less likely to repin images with price tags. One site, which averaged 135.6 repins per pin, only received 54.6 repins on items with $ signs, the study found. A major group-buying site fared even worse, averaging 0.2 repins on pins marked with a dollar sign, versus 1.8 repins on pins that bore no sign at all:

Why the behavior shift? Yang and Pinreach suggest that when users include $ in their pin descriptions, it doesn’t feel overtly commercial, but when brands do, it does. “When Pinterest users see $-pins from brands, it feels very much like an advertisement to click-through and buy, and they are less likely to share (i.e., repin) advertisements, as it degrades their own social proof with their followers,” the study reads.

The lesson here is readily apparent: If you’re a brand and want your products to be shared, don’t affix a price tag. But the study also underlines users’ more subtle aversion to brand-driven commerce within the Pinterest environment, even as a growing contingent of users prove eager to purchase products found on the site.

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