The data found that in the last three months of 2020, 8.4% of all ad mail, which includes direct mail, door drops and business mail, drove traffic to advertiser websites; while 5% prompted consumers to look up their account details. Both of these measures were up by nearly 50% year-on-year.

Furthermore, 5.7% of all ad mail and business mail prompted a purchase in Q4, representing 19% growth year-on-year.

The frequency of interaction with mail – JICMail’s measure of mail exposure – has remained virtually flat year-on-year for direct mail and business mail.

However, consumers have displayed improved engagement with door drops, with frequency growing by 9%. The average door drop is interacted with 3.06 times per month, direct mail 4.4 times and business mail 4.88 times.

JICMail said the fact that the rate of growth in mail frequency of interaction was outstripped by the growth in commercial impact in Q4 was “crucial” as it means mail “is driving effectiveness with even greater efficiency than before”.

Mail is also spending longer in the home than a year ago. The average piece of direct mail is in the home for 8.1 days before being filed or thrown away/recycled, representing growth of 4% year-on-year.

Door drops were found to be the biggest beneficiary of improved mail longevity, however, with growth of 17% year-on-year and average lifespans of 6.3 days.

Door drops containing vouchers and coupons and information about local services were key content drivers of lifespan growth, with the former staying in the home for a week on average, and the latter for nearly nine days.

The data also found that grocery, retail, local tradesperson and restaurant/takeaway sector door drops were the biggest contributors to the channel’s improved lifespan metrics in Q4. For direct mail, financial services and retail have driven growth in consumer mail engagement.

“While JICMail has for some years established the case for mail in above-the-line campaigns through the huge numbers of ad impressions that the channel generates, it is encouraging to see how efficiently those impressions are now converting into real commercial outcomes for brands,” said JICMail director of data leadership and learning Ian Gibbs.

“The accurate measurement of mail effectiveness should be a key concern for all measurement models – from econometrics to attribution models to brand trackers – if the channel is to be credited with effectiveness more accurately.”

JICMail data is gathered from a panel of 1,000 households every month. The mail activity of every household member is tracked using a diary-based app. Every mail item they receive over the course of a week is captured and everything they do with that mail item over the course of a month is recorded.

A recent Printweek briefing looked at how JICMail data for earlier parts of 2020 had already highlighted the increasing effectiveness of mail as more people spent time indoors due to lockdowns and working from home measures.