Hi,
In today's world, there are many different ways MBA is delivered - full time, executive and online being three most common ways.
Doing an online MBA is not necessarily the best use of your time and resources. This is because most organisations value people who have "risked" significant part of their income and time to furthering their career. It doesnt mean that an online MBA isn't relevant at all - it just means that if you are looking to change careers, progress into consulting or finance (IB, PE or VC) without finance background or change location, you won't have enough leverage to do so.
Hope that helps,
Please don't hesitate to contact me should you have any further questions.