The report predicts a 43% increase in consumer and B2B email volume from 3.2bn in 2005 to 4.6bn in 2006.
This reults mean that email could catch or even overtake consumer and B2B direct mail volumes, which are on a downward trend. The 5.1bn pieces of direct mail sent in 2005 represent a decline on 2004 of 5.3%, according to Direct Mail Information Service figures.
However, response rates for email have dropped to one of their lowest levels to date, according to the quarterly report.
The average acquisition campaign unique click-through rate for the final quarter of 2005 was 4.48% and the average retention campaign unique click-through rate was 8.53%.
In his introduction to the report, Dave Chaffey, email marketing consultant, said: "The popularity of using email for marketing communications continues to increase unabated... but reviewing click-through rates suggests that increased inbox volume has resulted in lower campaign responsiveness."
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