Acquisition and retention · Two-year randomized field experiment with a three-stage conversion model
Longer or shorter? A large-scale randomized field experiment on the impact of free trial duration on sustainable user conversion in the Freemium model
Zhang, L., & Duan, J. (2025). Frontiers in Psychology, 16, 1568868.
Plain-English take
In one global Freemium SaaS experiment, a seven-day rather than three-day premium trial increased trial adoption and delayed conversion, but did not significantly change immediate conversion. For your marketing: measure conversion stages separately and test trial duration in your own product.
How much weight to give this
5/5 Strong design for its specific question
The 1–5 evidence-check score is a practical reading aid, not a formal peer review or a probability that a conclusion is true. It combines design strength (2 points), sample reporting (1), comparison/control clarity (1), and how much of the paper could be checked (1). Access affects how confidently this directory can assess a study, not the study's underlying quality. Blinding is reported separately because it is not relevant to every design.
Random assignment provides a strong comparison for effects in the tested setting.
The paper reports 680,588 users across 190 countries; size does not guarantee a representative sample.
The paper compares a three-day control trial with a seven-day treatment trial.
The full article is open access and a linked publisher correction was checked.
Double-blind? Blinding is not reported in the article reviewed; that does not establish whether blinding was or was not used.
Research question
What the authors investigated
In a Freemium SaaS setting, how does premium-trial duration affect trial adoption, immediate paid conversion and delayed conversion?
Design
The authors report a two-year randomized field experiment comparing a standard three-day trial with a seven-day trial at an anonymized global image-editing SaaS provider. They use user-level behavior data and a local average treatment effect framework to evaluate a three-stage conversion funnel.
Sample and setting
680,588 new users across 190 countries during 2023–2024 at one leading global image-editing SaaS company. The provider and product are not named.
Reported result
What the study found
The seven-day trial increased trial adoption by 11.098% and delayed conversion by 42.36%, while the experiment found no statistically significant effect on immediate conversion. The paper also reports that longer-trial users responded more to feature-based promotions, while shorter-trial users were more sensitive to price incentives; effects varied with product functionality and market context.
This is a paraphrase of the source. Check the original paper for definitions, estimates, statistical uncertainty and analysis details.
Scope and transfer
Limitations to keep in view
One anonymized provider and product, one historical period, two trial lengths and a Freemium access model. The reported stage-specific outcomes and promotional interactions may not transfer to another product, audience or trial design. A 2025 correction adds an omitted author affiliation; it does not change the reported findings.
Possible founder application
Use this as a measurement-design example: separate trial adoption, immediate conversion and delayed conversion, and predefine how product use and promotional treatment will be analyzed. Estimate the effect with a local experiment rather than importing the reported percentages.
Evidence access
Open-access full text; an affiliation correction is linked
The full open-access article was reviewed for the experiment, sample, comparison and findings. The publisher correction was checked and concerns the author’s omitted affiliation.
If only an abstract or metadata was available, the profile is limited to claims supported there. A paper's paywall does not change its evidentiary status, but it limits what we can substantiate from accessible text.