Summary.    Customers often need time to evaluate a product or think about their experience with it before they decide to post a review. If they’re asked to provide a review too early, they can feel pressured and rushed. But when is the right time to do it? The authors...

Businesses in numerous marketplaces today send review reminders to customers shortly after they’ve bought a product or paid for a service. These businesses are operating under the assumption that these reminders will boost the number of reviews they receive. That’s a reasonable assumption: With the passage of time, customers naturally become less likely to post reviews. When viewed against this backdrop, it would seem to make sense for businesses to send review reminders at the earliest possible time.

But does it? Consider the last time a company sent you a review request. How quickly did it come? In all likelihood, you received the request quickly — so quickly that you found it somewhat irritating. Customers often need time to evaluate a product or think about their experience with it before they decide to post a review. If they’re asked to provide a review too early, they can feel pressured and rushed, and they might opt not to send in a review at all. One survey has revealed that the majority of online customers today take at least two days after getting a product to post a review, while only 8% choose the same day.

To examine this process more closely, we conducted two randomized, controlled field experiments. We created four distinct time intervals for review reminders: the next day, five days, nine days, and 13 days after the product experience. For each timing class, we assigned customers to the treatment or control group at random. A review reminder was sent to the treatment group but not to the control group.

Contrary to conventional wisdom, our results indicate that immediate review reminders (sent the next day) lower the likelihood that customers will post reviews, relative to a randomized control, whereas delayed reminders (13 days later) increase the likelihood. However, there was no significant difference in the likelihood of a review being posted when reminders were sent five or nine days following the product experience. The main reason for this seems to be that although reminders serve as a modest memory boost, they also interfere with customers’ feelings that they are free to post reviews whenever they’d like. That interference creates a negative motivational state known as psychological “reactance,” which outweighs the effect of the memory boost.

Against this backdrop, how should businesses determine when to remind their customers to provide reviews? Our findings suggest that the following approach is best:

1. Figure out how long, on average, it took customers to post reviews for your product or service in the past.
2. Check to see if the average amount of time has passed.
3. If no, do not send a review reminder. You don’t want to interfere with your customers.
4. If yes, then send a review reminder to the customer.

We made two other findings in our study that have nuanced implications for businesses when it comes to the customers they serve and the product categories they provide.

First, immediate reminders are especially negative for businesses with young customers. Generation Z have always used online platforms and online review sites, which makes them true natives in the digital sphere, with a strong sense of autonomy there. Immediate reminders are therefore very likely to undermine their sense of autonomy online.

Second, the right time to send a review request also depends on how soon after buying or using a product or service it can be evaluated for quality or fit. Food, hygiene, and office supplies are examples of items that may be promptly appraised after purchase or consumption, whereas furniture and appliances need more time to evaluate. Thus, sending an early reminder for paper towels, bottled water, and canned soups may be okay, as customers know what they bought and whether it’s good after usage. In contrast, restaurants, beauty salons, and travel may benefit from giving customers enough time to evaluate the product or service before sending a review reminder.

The bottom line is simple: When it comes to review requests, businesses should not mindlessly adopt strategies such as “faster is better” or “one-size-fits-all.” Instead, in order to elicit more reviews from customers, they should reevaluate their current tactics and adjust the timing of review reminders in accordance with the specific market and geography they serve and the goods and services they provide.