Why your weekend reviews may be more negative

It is Saturday. You’re relaxing with a coffee, and you finally have time to leave a review of the restaurant where you dined during the week. You open the relevant app, select a star rating and submit your review. But do you realize that the day on which you write the review could change how positive or negative it is?

New research suggests that it can. A study by Verena Schoenmueller (Esade), Andreas Bayerl (Erasmus University Rotterdam), Jacob Goldenberg (Reichman University), and Florian Stahl (University of Mannheim) finds that online reviews submitted during weekends tend to be more negative than those submitted during the week.

These are surprising results. Previous studies have tended to associate weekends with better and happier moods. Yet this positive mood does not appear to translate into more positive online reviews.

The researchers found a weekend effect

Published in the Journal of Marketing Research, the study analyzed almost 400 million reviews across 33 online platforms, covering more than 20 million products, businesses, services, movies, employers, and more than 60 million users. The platforms included Amazon, Glassdoor, Yelp and IMDb, among others.

In 26 of the 33 datasets, reviews submitted during weekends were significantly more negative than those submitted during weekdays. Overall, weekend reviews averaged 0.04 stars less than weekday reviews. Compared with weekday reviews, weekends saw a 3% lower relative share of five-star ratings and a 5.7% higher relative share of one-, two-, and three-star ratings.

These results were seen across a wide range of businesses, sectors, and countries. The pattern was remarkably consistent across different types of platforms and locations, suggesting that something deeper than the actual customer experience was influencing when people leave more negative reviews.

It isn't necessarily that the product or service is worse

So why could we be seeing more critical reviews at weekends? Perhaps experiences are genuinely worse? Restaurants could be overcrowded, queues longer, and staff under more pressure. The researchers assessed these ideas and found that although crowding can contribute to the effect in some travel, restaurant and experience settings, it cannot explain the wider pattern.

This ‘weekend effect’ also appears for products, software and employers, where the underlying quality is unlikely to change just because it is Saturday. Even when the researchers compared the same listings and controlled for other factors, the effect remained much the same. In one dataset of reviews of legal consultations, for example, the quality of consultations was almost identical on weekdays and weekends, yet reviews still showed the weekend effect.

So the explanation as to why reviews for products and services are more negative at weekends lies less in what is being reviewed and more in who is choosing to review it.

The person behind the review matters

According to the researchers, what is going on here is a phenomenon known as ‘temporal self-selection’. Simply put, the people who choose to write reviews at the weekend are not necessarily the same people who write them during the week.

People who wrote reviews only at weekends tended to give lower ratings than people who reviewed only during the week. They also used different language. Weekend-only reviewers did not refer as much to friends, family, and other people in their write-ups. Furthermore, additional evidence suggested they had fewer social connections.

As the co-authors put it, the weekend effect is less explained by where a review is submitted or what is being reviewed than by who submits it.

Online reviews are already a selective form of feedback. People choose whether to leave a review, and that decision is influenced by their experiences and motivations. The new research highlights the importance of timing when submitting that review.

A small difference can have a big impact

A difference of 0.04 stars doesn’t sound significant, but it can still have a meaningful impact. The researchers show why. Imagine an Amazon listing with just three reviews. If a product with three reviews averaging four stars receives one additional one-star review, its average falls to 3.25 stars. For businesses and products with few reviews, a single negative rating can therefore have a disproportionately large effect.

This is why concerns about online reviews have become so significant. A recent Medium article, for example, explores the concerns among business owners about the potential damage caused by negative Google reviews.

Fake reviews have become such an important issue that US authorities have taken action to address them. In 2024, the US Federal Trade Commission introduced a rule prohibiting practices including buying or selling fake reviews, paying for reviews conditional on positive or negative sentiment, and certain forms of review suppression.

So should businesses stop asking for reviews at weekends?

Do businesses need to carefully time when they ask for reviews? To answer this question, the researchers conducted five additional studies to examine whether businesses could influence the weekend effect by changing when they asked customers for reviews.

The studies included randomized experiments and a field experiment. Across these different settings, the results were consistent with the original finding: asking for reviews during the weekend can produce a more negative set of responses.

For businesses seeking to reduce the likelihood of negative reviews, the researchers suggest making review requests during weekdays. In this way, businesses can think about review requests as a tool to use proactively to deliberately try to encourage reviews to be written during weekdays.

When should we believe a rating?

Potential customers take a business’s star rating very seriously. A 4.2-star rating gives us more confidence in a business than a 4-star rating. Given the weight consumers place on reviews, business owners would be wise to consider the timing of review requests so as to optimize for the likelihood of positive reviews.

In an increasingly digital marketplace, providing good customer service isn’t necessarily enough to guarantee a glowing review. The day on which someone chooses to write a review may influence who contributes to the rating, just as the timing of the request may influence who responds. This research raises the question: if ratings can depend partly on when and why people choose to provide them, how much can a star rating really tell us about quality?