The Independent (4 January 2011) attempts to identify the number number of people reverting to Islam in the UK and speculate about their reasons why in an (somewhat sensationally-named) article entitled: "The Islamification of Britain: record numbers embrace Muslim faith"
It cites a number of sources for figures around how many people have become Muslim, but highlights a figure from the thinktank Faith Matters of as many as 100,000 reverts and as many as 5,000 new reverts each year. As to why, the article quotes a number of reverts:
"The fact that the Qur'an is the same now as it ever was means there's always a reference point. The issues of women's rights were shockingly contemporary. The more I read, the more I found myself agreeing with the ideas behind it and I could see why Islam coloured the lives of my Muslim friends. It made sense, really, I didn't and still don't want to be Muslim, but there came a point where I couldn't say that I wasn't Muslim."
"I was very ignorant to Islam for most of my life and then I went on holiday to Morocco, which was the first time I was exposed to Muslims. I was literally a racist before Morocco and by the time I was flying home on the plane a week later, I had already decided to become a Muslim."
"I liked the way the Muslims students I knew conducted themselves. It's nice to think about people having one partner for life and not doing anything harmful to their body. I just preferred the Islamic lifestyle and from there I looked into the Qur'an. I was amazed to see Islam's big emphasis on science."
"Everything is so consumer-driven here, there are always adverts pushing you to buy the next thing. I knew there must be something longer term and always admired the sense of contentment within my colleagues' lives, their sense of peace and calmness. It was just one of those things that happened - we talked, I read books and I related to it."
"I know it sounds odd, but one day I was Tracey the Christian and the next day I was Khadijah the Muslim, it just seemed right. The only thing I knew about Muslims before was that they didn't drink alcohol and they didn't eat pork."
You can read the full article here.