How Product Image Size Impacts Value Perception [Original Research]

What makes a good product page?

Well, there are tons of elements that come together to make a successful product page. These include price, product image, product copy, layout, etc.

One element in particular, product image size, seems to affect the value perception of the product. In this study from CXL Institute (part one of three of a full eCommerce product page study, the others to come soon), we look at product page design, and in particular, how you can increase the value perception of your particular product.

Results summary

• The average perceived value for the large image of the hard drive (search good) was $13.50 more than the smaller image.
• The average perceived value of the shirt (experience good) was $1 less when the image was larger. In other words, participants perceived the shirt to be higher quality/more valuable when the product image was smaller and there was more white space on the product page.

How do I apply this research?

• If you sell a spec-heavy search good (e.g. a hard drive, printer, camera, etc.), test a larger image on your product page.
• If you sell a design-heavy experience product (e.g. a shirt or some other wearable), test more white space on your page (to minimize visual complexity). In our tests, all 3 website variations with more white space resulted in higher perceived value (due to image size and other web elements).

Full study setup description

This experiment consisted of 3 distinct studies aimed at testing hypotheses regarding the layout presentation of e-commerce product pages, specifically:

1. how pricing perceptions change with image sizes
2. how people visually perceive the page with differing image sizes (coming soon)
3. how the presentation format of the specification/description text affects how people visually perceive the page (coming soon)

We test these hypotheses across product 'classes.' The product classes we use vary according to the commonly used ‘experience-search’ product classification, an economic theory developed by Philip Nelson. We use a men’s dress shirt as an ‘experience' product, an external hard drive as a ‘search’ product, and a pair of over-ear headphones as a hybrid.

Product type can also be characterized by a 'design-spec' range as well. The idea behind this range is that some products' value are derived from their overall design (the shirt) while other products are defined by their specs (the hard drive). The headphones represent a hybrid product since both design and specs contribute to their value.

Does Image Size Affect Value Perception?

It seems like such a minor thing, but can increasing the product image increase how much people think it’s worth? That’s what we set out to study. Here’s the background of our research…

Hypothesis: Large product images on product pages result in a higher perceived value compared to smaller product images on the same page. In other words, people will perceive a product to be more expensive/valuable when its display picture is large.

We also wanted to understand if this effect was more pronounced in different product categories. So we tested a product from each end of the spectrum, from “experience goods” (products that are hard to evaluate before consuming/using them) to “search goods” (products with features that are easy to evaluate before consumption).

The study treatments included a dress shirt product page and a hard drive product page. The dress shirt test had unexpected results, opposite our hypothesis, so just to add some validity we replicated the test on two additional websites, varying in design characteristics and price point. The dress shirt represents an experience good while the hard drive represents a search good.

For the dress shirt, product image and brand logo remained consistent across all three treatments and acted as control variables. The size of the product image acted as the treatment variable and varied across the three websites. Any prices and indications of price were removed from the pages.

Each treatment (n = 8; 6 shirt & 2 hard drive) were sent to around 300 people (specific numbers below). We asked two pricing questions:

1. At what price is this product a bargain?
2. At what price is this product too expensive to consider?

These questions are a modified version of the Van Westendorp Price Sensitivity Meter.

For all surveys, our audience was limited to a United States general population, and participants were limited to only one treatment, resulting in 2,982 total participants. Here are the numbers per treatment:

Shirt (a) Variation

Variation one: This website was the original source, except we either enlarged or reduced the shirt image size for the treatment variations. The original price of this shirt was $145.

Shirt (a) Statistics

Shirt (a) Results: What’s the Takeaway?

• The smaller image actually produced a higher perceived value, significantly so for the ‘bargain’ question in a t-test (p-value = 0.012) and nearly so for the ‘too expensive’ question (p-value = 0.117).
• It’s likely that with additional responses, the ‘too expensive’ question would’ve produced significant results as well. As of now for this ‘too expensive’ question, there’s 94.1% certainty that the smaller shirt image has a higher perceived value (smaller shirt mean > larger shirt, p-value = 0.0587).
• Not only does this make us reject our hypothesis, it flips it. We now have evidence that a smaller image can not just change but increase value perception (at least for a men’s dress shirt, a clear ‘experience’ product).
• An alternative hypothesis that we now want to test is whether the effects of simplicity and more whitespace increase value perception more than a large product image can.
• This is why we tested the two additional shirt variations below, both had ‘busier’ displays.

Shirt (b) Variation

Variation two: Here we’ve modified a Macy’s product page which is generally a busier design (e.g. core colors, text, elements, etc.) than variation one. The price of the shirt originally shown on this page was $52.50.

Shirt (b) Statistics

Shirt (b) Results Summary

• There were no significant results between image sizes for either question. However, the pattern of lower value perception for a larger product image exists.
• Although not significant at the 0.05 level, there’s a 78.5% chance that the means between the small and large product images are different for the ‘bargain’ question.

Shirt (c) Variation

Variation three: The last variation is a modified version of an Amtify shirt product page. The price of the shirt originally shown on this page was $29.90.

Shirt (c) Statistics

Shirt (c) Results Summary

• Again, there were no significant results among the image sizes for either question. However, the pattern of reduced value perception for a larger product image does exist.
• However, this one is closer to significance than the Macy’s variation. There’s an 83% chance that the ‘bargain’ question resulted in different means between the image sizes, and a 91.5% chance that the small image mean is greater than the large image.
• This result shows a stronger pattern compared to the Macy’s variation. This product page is visually less complex than the Macy’s page, which is a theory on why this result is stronger than the Macy’s variation but weaker than variation one’s simple design.

So, what about search goods?

Hard Drive Variation

We modified the product page here.

Hard Drive Statistics

Remember, our hypothesis was that the larger image would translate to a higher perceived value and that the ‘experience’ type of product (shirt) would show a larger difference among image sizes compared with the ‘search’ type of product (hard drive).

Hard Drive Results Summary

• This ‘search’ or ‘spec’ product category confirms our hypothesis that a larger product image will increase value perception. And it did so with pretty large numbers, especially compared to the shirt variations.
• When asked “at what price is this hard drive a bargain?” respondents perceived the product page containing the larger image to be 11$ more valuable than the hard drive product page with the smaller image.
• When asked “at what price is this hard drive too expensive?” respondents were willing to pay $15 more for the hard drive with the larger product image.
• The difference between perceived value in the ‘bargain’ question was significant (p-value = 0.039), and the difference in the ‘expensive’ question was nearly so (p-value = 0.053). Pretty strong results here.

Conclusion

What we found was surprising.

We thought that larger images for experience goods (like shirts) would be viewed as more expensive/valuable. However, it was the opposite. People viewed experience goods as less valuable (generally) when larger images were used.

However, it was the converse for search goods (like hard drives). Larger images made people perceive the products as being more expensive/valuable.

Note: this is a 3-part series on e-commerce products. Make sure to check out study 2 and study 3 as they come out in the next week or two.

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