By Michael Brenner for Marketing Insider Group It’s time to start thinking about your holiday marketing campaign. No matter what your business, there’s always a way to work in a little holiday cheer into your end-of-year marketing. There’s one character, though, you don’t want to creep through. Scrooge. But what if your employees think you’re a bit of a Scrooge? How engaged are they at work? Only about 30 percent of the nation’s employees are engaged on the job, according to a Gallup survey. And if they’re not, all you need to do is glance at the mirror to see Scrooge’s shadow.…