Just over a third of businesses (34%) are unable to calculate the revenue earned from email marketing, according to a new survey from the DMA.

Only 60% of respondents said that they could calculate the revenue return, despite the fact that a vast majority of businesses (89%) said email marketing was either ‘very important’ or ‘important’.

This tallies with data from the new Econsultancy/Responsys Marketing Budgets 2013 Report, which found that only 52% of businesses rate their ability to measure ROI from email marketing as ‘good’.

According to the DMA’s report, of those who can calculate the ROI one-fifth (20%) accrue more than £51 for every pound spent, while almost a half (49%) of respondents said they achieve an ROI of between £1 and £10 for every £1 spent.

Even so, based on an assumption that the average return for the top category is £55, the estimated average return across all organisations is £21.48 for each £1 spent on email marketing.

The report also found that more than half (56%) of respondents expect their company’s email budget to increase in 2012, while only 5% said they expect it to decrease.

Our Marketing Budgets Report revealed similar findings – 65% of respondents said their email marketing budget would increase this year, while just 4% said it was likely to decline.

Interestingly, the DMA’s report found that lack of internal resource (54%) and budget (38%) are the main constraints preventing companies from achieving their marketing goals.

Lack of data was cited by just 27% of respondents, while internal process and in-house technology were selected by 30% and 28% respectively.

Another indicator of the value of email marketing is its share of business revenue. The majority of businesses (62%) produce more than a third of their digital business revenue through email.

In fact a third of businesses (34%) achieve 50% or more of their digital revenue from email marketing.

The DMA's survey, sponsored by Alchemy Worx, polled 250 senior B2B and B2C brand marketers.