With millions and millions of users around the world, an ad campaign featuring Danny DeVito, and its own conference, Intuit QuickBooks might be the most popular small-business software-let alone accounting software-in the world. If you were creating a “small-business owner” Halloween costume, it would probably include a button-down shirt with rolled-up sleeves, a travel coffee mug, laptop computer covered in stickers, and a copy of QuickBooks Online accounting software. QuickBooks might be the most popular business software in the world, but that doesn’t mean it’s the right fit for every business.