Off-topic too but are all Mormons successful, or do we (the world-wide general public) just see them because they talk about being wealthy, successful and Mormon at the same time, and the evangelists give the impression too because they all wear well-cut suits?
A look at Utah's various statistics you might want to use as measures of overall success ought to paint a different picture, also visiting different areas of the state for a while will too. But that's not to say you'd be wrong in giving a higher prior for success after hearing someone is a proper Mormon (and many Mormons the world generally hears about are even if the majority aren't and will never get a temple recommend). Proper Mormons don't drink alcohol, smoke, or drink caffeine, they try to marry young, have children, stay in contact with their (extended and large) families, are active Church-goers (and hence active in the Community), and they pay an extra tax to the Church without becoming financially crippled. This is basically an immense filter for self discipline / resistance to temptation and solid social networks, which tend to be factors with a lot of successful people.
Not all by any means. But the church does encourage self-reliance, frugality, saving, education, emergency preparedness, and hard work; promotes stable families; and discourages various expensive and life-destroying vices.