Econsultancy said the market is flourishing as firms focus on areas of marketing that deliver proven return on investment.
By comparison to other digital marketing channels, Econsultancy says the UK paid search market-place was worth £2.4bn during 2008 and UK affiliate marketing was worth around £3.8bn in 2008.
Econsultancy data shows that only 8% of e-mail marketers said they were using a fully managed e-mail marketing service, while 47% were using a hosted service and 23% an in-house system.
However, 32% of firms are spend- ing less than £5,000 annually on e-mail marketing. Yet, at the other end of the scale, a further 34% are spending at more than £25,000.