Agree with previous, you will want to be using a business account for all your assets under Pinterest, even for accounts specifically for testing or dumping pins to discover new niches or sub-niches.
While it seems obvious to some, the other underrated benefit of using a Business account for most newcomers is Pinterest Analytics = Data = Money.
Why would you want to post countless hundreds/thousands of Pins under a personal account with limited to no data available to you from Pinterest's side?
When you could be mining for gold going into Pinterest analytics, exporting the data, and seeing what is working and what is not on a weekly/monthly basis to better help your direction or approach?
Whether you plan to Pin using bots/schedulers (mass pinning) or take a far more manual/considered approach. This data is still valuable per account and helps you build a better picture of the direction you are going, not to mention it helps you discover new trends, pin designs that work, pin keywords that bring money, titles that get the clicks, boards that are hitting the spot with Pinterest, etc.
