Another 11% also cleaned their data after each campaign but manually, and 6% admitted to never cleaning data at all. As many as 32% cleaned on an ad-hoc basis, 9% did so monthly and 5% weekly.
The figures come as IPT releases the second part of its 'Essential Industry Guide to Email Marketing', which focuses on best practice in data collection and management, in particular cleaning, targeting, segmentation, seeding and compliance with the latest legislation and directives.
Martin Kiersnowski, chief operations officer at IPT, believes that confusion among marketers about legislation on data collection is restricting their usage of third-party email lists, which IPT provides.
IPT surveyed what email data collection methods marketers used and found that 81% used their own website, 9% used third party opt-in lists, 3% used list rental, 2% used paper-based surveys and 1% outbound phone surveys.
According to Kiersnowski: "The use of email for customer acquisition depends on prospect email data collection -- we explain that there are many more ways of doing this, in volume two of our guide, than by offering website registration.
"As for opt-in email lists, these are improving in volume all the time and will soon be at the level of the direct mail industry's lists."
The second part of the guide is available free at IPT's .
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