"When we think of an idea, we don't ask for a person to spend 5% of his or her time on it," says Anthony. "We say, 'This is your focus for three to six months.' If you're serious, you need to commit them to it."
Case in point: When one of Anthony's partners at Innosight wanted to create a new business focused on incubating and investing in startups, the other partners gave him the freedom to spend all his time on the project. Innosight has since invested in three successful international companies -- a business that wouldn't have been built if pursued part-time, says Anthony.
Moving from brainstorming to action can be tough, entrepreneurs admit. Set goals and benchmarks -- time or money -- for your idea so you know when to quit.