The fact that Quaker-founded firms (such as the recently sold Cadbury) had such influence is particularly interesting when you consider the relatively small numbers of the faithful (less than 0.1 percent of the population of 21 million in the UK in 1851). But it seems that an informal fraternity of Quaker candymakers led to business networks that helped all of them get a leg up on their non-Quaker countrymen, and a straightforward "no-haggle" pricing scheme helped solidify relationships with customers.
If you're a business, candy, or labor history buff, this is a story worth reading.
Oh, and Quaker Oats? Totally not Quaker, at any point!
It's worth noting that in the States, Milton Hershey was a Mennonite, one of the Old Order Brethren (Quakers, Amish & Mennonites).