Have an Answer?
Financial Services covers such a wide spectrum within finance, it's tough to give a brief answer. Think about it from a personal standpoint. Majority of population has a checking and savings account where they hoard their money while trying to get paid some type of interest (but not in today's low interest rate world) for their deposit base. The banks use that deposit base and use leverage to lend it out at much higher interest rates. They do this for car loans, mortgages, bank credit cards, commercial loans, business loans etc.
Now think about a brokerage account (account to buy/sell stocks, bonds, options, mutual funds etc.) or wealth management accounts. Typically, public companies (traded on exchanges) have security instruments that are traded in the market place or exchanges. Many financial institutions such as B of A Merrill Lynch, Goldman Sachs, Credit Suisse, Barclays and others are all competing with each other to win over small and wealthy customers to make those financial securities transactions through them which in turn generates more $$ via commisions or asset mgt. fees for the firm.
Finally, think of financial services simply this way: Person A walks into a store with money in his pocket (customer/client) and looks around the store. Person B is behind the cash register (bank/service provider) and assists Person A with advice on what product he desires. If there is a fit, then a transaction finalized.
Is it a successful career choice? That is all based on the desire and genuine passion within the individual who is pursing it. There are a lot of people in this field who are miserable just like other industries.