A UK Gambling Commission study found that, contrary to their expectations, the internet has not led to an increase in the proportion of people gambling from the previous study in 1999.

Problem gambling remained at the same level as found in 1999, at about 0.6%, or about 250,000 people in the UK.

I wrote earlier about the absurdity of USA-style prohibitions of online gambling:
You cannot gamble online either. You used to be able to - but then, a Las Vegas representative introduced legislation that cracked down on online gambling. And playing poker, too. Ostensible reason? Poor children who gamble online and get their parents into enormous debt. That's what the TV said. Real reason? Las Vegas casinos feeling competition from the online gambling industry. So they lobby the federal government to prohibit you, and everyone else, from doing what you want with your money. And it considerably hurts freedom on the internet, because now, all of a sudden, it becomes more difficult to make online trasactions - there need to be all these checks to make sure none of it goes into gambling. And all of that, for what? The benefit of Las Vegas casinos?
This new study shows how groundless, pointless and useless these prohibitions against online gambling really are.