Advertising does not prove that something is independent. The Company is just fine with their employees earning a little money on the side. In fact, the employees get to keep that money. When you operate "under cover" doing psy-ops, and part of your cover is working at the chicken place, you don't turn over your paychecks to the Company--you get to keep them. Similarly, if you run a blog for a company, any advertising revenue you get is yours.
That's a notable part of retirement packages, actually. You get these people who've been in the newspaper business for however many years, planting articles and controlling reporters, and they do not have to return any of the fruits of their labor. Editor's paycheck, gold watch at twenty years, the downtown condo to start them off, the master's degree that made it all plausible--tax free benefits, through and through. Plus they still get their $70K/year from the Company, and they get their pension and health care benefits, and Social Security, but they also get anything they kept during a job.
An inundation of advertising is expected these days. Makes it look like a page is a "real" page. Some of the bigger operations, like Cracked.com, might deposit into a Company operating account, but individual operators creating multiple profiles to disseminate minor cultural movements, are permitted to sign up with Google and make money personally, too. The absence of advertising doesn't make anything immediately less suspicious, but don't let the presence of advertising trick you into thinking it's a real opinion.