Project managers with PMP certification earn more. Surveys show that project managers with PMP certification earn an average of $20,000 more annually than their non-certified counterparts.
Some employers require certification. If you are in the market for a job as a project manager you may find that in many cases employers actually require certification of their project managers, and will not hire non-certified project managers.
It will make the job search shorter and easier. Having the PMP certification credential will certainly make it easier to find a job as a project or program manager. All else being equal it will give the applicant the edge over on who is not certified making the job search likely shorter and easier. It will also serve to help close the gap if you are up against applicants with more experience.
Being PMP certified proves that you have project management experience. In order to apply to take the PMP exam you are required to have attained a certain amount of experience leading and directing projects: 60 months (7,500 hours) of experience if you have an associate’s degree, and 36 months (4,500 hours) of experience if you have a bachelor’s degree. PMI (the Project Management Institute) has an audit process to help ensure that potential PMPs are being truthful about their project history - thus legitimizing the resume to a degree.
Training is guaranteed in many cases. Training to help you pass the difficult PMP certification exam is not required but extremely helpful for most individuals and often comes with a guarantee. For example one organization - Cheetah Learning - offers a 4 day course of training - ending with the actual PMP certification exam. If you don't pass you train and take it again for free or you can also get a refund. Either way you won't have to pay twice.