Mailing lists: Why data quality is so important

The quality of the contacts within your mailing list is crucial, because it will have a huge impact on the results of your campaigns – and on your business’s future reputation.

Cheap is definitely not cheerful when it comes to choosing a list provider.

The effect of GDPR on data quality

The importance of data quality, these days, ties in with the General Data Protection Regulation (GDPR). One of the key components of GDPR is maintaining accurate and frequently cleansed contacts in all of your data records, including any lists that you buy in, so you need to be vigilant and disciplined.

Records should be telephone-screened by your supplier at least once every 12 months, and TPS/CTPS-checked every month.

Keeping on top of contact churn

There will always be a small margin of error in your marketing data. People move from job to job, and companies come and go.

No list is 100% accurate at all times, but a reasonable expectation is that each record on the list is checked once every 12 months, so that the entire list is always 95% accurate overall.

Be wary of trusting data from Companies House

You’ll benefit from having a clear understanding of the data you’re renting.

With b2b marketing lists, a common mistake that many businesses make is renting or using Companies House data.

It does seem logical that Companies House would be the ultimate source of accurate and reliable data, but this is actually not the case for marketing lists.

Of the several million companies registered on the Companies House database, about 50% of them are either dormant, shell companies, holding companies or active companies registered at their accountant’s/solicitor’s addresses.

On top of that, Standard Industrial Classification (SIC) codes are often vague – i.e. ‘other services not elsewhere classified’ – and a lot of ‘directors’ are not active in the businesses at all.

Of course, a lot of the financial information is good and accurate, but to try and use Companies House data for a marketing list from an online solution is often disastrous for sales and marketing campaigns.

This is why it’s always best to work with a data marketing consultancy to buy your lists, rather than buying access to an online system. With a proper consultant, quality is assured.

Further reading: Data HQ's complete guide to marketing lists and Data HQ's complete guide to data quality