Financial advisors are leaving millennials out in the cold when it comes to looking for more clients. 

So says a new study conducted by Harris Poll for the Principal Financial Group, which revealed that only 18 percent of survey respondents target Generation Y as a source of new clients. Instead, they look for baby boomers (64 percent), the affluent or high-net-worth individuals (64 percent), or business owners (62 percent).

Considering that more than half of advisors (57 percent) prefer their new clients to have assets of more than $250,000, it's no wonder they're not spending a lot of time with millennials. But that could be a mistake, because millennials (ages 18-37) make up a 7 percent larger portion of the population than boomers and have plenty of years ahead to save for retirement and work toward other financial goals.