Strengthening user trust through real user numbers and star ratings in the Hero area
Result:
Software
Germany
+ 16% Sales
Table of contents
About Buhl
Buhl Data Service GmbH is an owner-managed German software company that was founded in 1986 and is based in Neunkirchen (Siegerland). As a specialist for SaaS solutions, Buhl develops and distributes software for tax returns, financial management and office processes - including the well-known WISO Steuer brand.
Initial situation
This case study examines how the integration of social proof elements in the hero area can strengthen user trust and increase the conversion rate. The experiment was conducted on the central marketing landing page of WISO Steuer (buhl.de/steuer) - the central point of contact for paid and organic traffic in connection with the brand's tax software.
As the primary entry point for new users, this page plays a crucial role in establishing credibility and motivating visitors to sign up. The test investigated whether adding visible trust indicators - such as the total number of users and star ratings - could improve perceived reliability and lead to more conversions.
Goal / Motivation
The primary goal of this test was to increase the conversion rate from visit to sign-up. Behavioral analysis and scroll depth data showed that many users left the site before interacting with deeper content, indicating that initial trust was not built early enough.
To address this issue, the team drew on UX best practices and behavioral psychology, which suggest that social evidence - specifically user numbers and reviews - can positively influence credibility and decision-making by leveraging the bandwagon effect.
Test setup
A multivariate test was carried out on the main landing page of WISO Steuer. As this page is the first point of contact for almost all traffic from Google Ads and organic search, even small improvements in trust perception can have a measurable impact on conversion.
The test included all visitors to buhl.de/steuer. It ran over 8 days with a sample size of over 35,000 users and a confidence level of 95.3 %.
Variations
Hypothesis
If users can see clear social proof - such as the total number of users and star ratings - directly in the Hero area,
Then the conversion rate increases from visit to registration,
Because these references create trust and security by showing that many others have already opted for the product and benefited from it.
Changes:
Original: Standard Hero area without social proof elements.
Variant 1: Add a real image icon with the text „Over 5.5 million satisfied users“.
Variant 2: Combination of the same user numbers text with a 5-star rating (4.9 out of 5).
Test results
Although the introduction of Social Proof did not lead to a measurable increase in sign-up conversions, it did lead to an increase in sales of +16 %.
Another finding was that variants with real people performed slightly better than designs that only contained symbols. This suggests that authentic images can help strengthen emotional trust and increase perceived credibility.
Summary & Learnings
The experiment was conducted with Varify, which proved to be an excellent choice thanks to its affordable prices and ease of use.
Thanks to its intuitive setup, we were able to quickly create and deploy multiple variants without the need for extensive developer involvement - a key benefit for a marketing team that often runs experiments on high-traffic landing pages.
Varify enables us to quickly turn ideas into experiments on our high-traffic landing pages for WISO Steuer. The tool is easy to use, fast to implement and fits perfectly with our in-house testing setup, helping us run more A/B tests with less friction and greater confidence in our decisions.
Head of Marketing - WISO Steuer
Head of Marketing - WISO Steuer, Buhl Data Service GmbH