How to increase conversion rate on Shopify by 7,1% with product detail page optimization


We introduced sticky buttons (CTAs) at the thumb zone (bottom of the screen) on PDPs on the mobile devices. These buttons allowed users to choose the size, metal and gemstone of a piece of jewelry with minimum effort. Because these buttons were always visible, they also effectively communicated to users that they could customise every piece of jewelry by metal (e.g. gold and silver) and gemstones (e.g. diamond, moonstone, opal).

The sticky buttons on PDPs increased the average revenue per user (ARPU) by 6.9% and AOV by 10.6%.


Overview is a fast-growing online jewelry store that has 430,000 sessions per month (according to Similarweb). It sells rings, necklaces, earrings and other jewelry.

Our task was to increase the revenue per user (ARPU) metric by growing the conversion rate (CR) and average order value (AOV).



As part of the user behavior analysis, we studied the user flow, and found that some users purchased the same products multiple times in a single transaction. When we looked deeper into this phenomenon we realized that users were purchasing multiple modifications of the same product. For example, a user may have bought a particular ring in gold with a diamond and the same ring in silver with an opal gemstone.

We did a regression model to identify products that are often purchased together, and found that about 7% оf transactions had more than one product of the same design in it.

Our research showed that there is a segment of users who purchase the same product in different varieties in a single transaction. The AOV and ARPU of this segment of users was among the highest of all segments.



We hypothesized that we could further the behavior of users purchasing the same product in different modifications in a single transaction, by showing possible modifications more effectively. Promoting this user behavior would increase the average number of items purchased per transaction and as a result increase the AOV and ARPU.



We created a variation where the option to select metal and gemstone on PDPs is done through sticky buttons in the thumb zone on mobile devices.

Control variation

Alternative variation


Validating the hypothesis

To validate this hypothesis, we conducted an experiment that measured the impact of the new UX on the ARPU, AOV and CR.

The experiment had the following characteristics:

Experiment type: A/B test

Traffic split: 50/50

Device: mobile

Key metric: ARPU

Secondary metrics metrics: AOV, CR and engagement with sticky CTAs

Number of sessions included in the experiment: 167,213 sessions

Number of conversions recorded during the experiment: 3,127 conversions


The new variation outperformed the control in all key metrics:

  • 6.9% uplift in ARPU
  • 7.1% uplift in CR
  • 10.6% uplift in AOV
  • 5.7% increase in average number of units per transaction.

The ARPU result showed a 95% statistical significance and power of 0.8.

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