There are more than 1,400 UK dating sites and the industry is expected to be worth around £150 million by 2014.
Of the 16 million singles in the UK, 60 per cent have tried online dating at some point.
The work highlighted interesting cultural differences. From the studies, Dr Warren created a questionnaire that e Harmony users are told to complete on signing up.
From that, a profile is generated used to match people. Speech and language therapist Morwenna White, 31, from Bristol, would say very well.
It's the chemistry that's the dealbreaker.' Yet Charlotte Martin, 28 , a market researcher from Manchester, says her experience of e Harmony has been disappointing.
Dr Warren spent 35 years counselling patients on relationship issues.
Yes, it's a dating site, but there's some intelligence going on behind the scenes.' Does this mean online dating has gone sensible on us? 'It was a case of dashing home, heart racing, each day to check for a message from Morwenna.
We were lucky - we were a match on paper and there was chemistry when we met in person.
But there's nothing to say that you wouldn't have amazing chemistry with a man who seems like a complete mismatch.' This hasn't stopped e Harmony boasting that 800 of its UK members are already in long-term relationships after meeting on the site.
They say there's also been more than 100 marriages and engagements among British members, too.