In a survey conducted by MarketingSherpa and ad:tech, 44 per cent of marketers quizzed said they received a great return on investment (ROI) from email marketing campaigns using their in-house lists.

Only pay-per-click (PPC) search ads generated a better approval rating, with 51 per cent of participants seeing a great ROI.

However, many more firms employed email marketing, perhaps because it is significantly cheaper than most forms of internet advertising.

The study also discovered that emailing to rented lists is far less effective than using in-house information. Almost half of those who used third-party lists said they generated a poor ROI, while only 12 per cent expressed satisfaction with their return.

Only pop-up and pop-under ads achieved a lower score, with nine per cent of marketers happy with their performance and 67 per cent reporting a poor ROI.

This finding came despite the Federation of European Direct and Interactive Marketing's recent suggestion that renting lists for direct marketing campaigns was more effective than building in-house lists, because compiling relevant data can be expensive and time consuming.