If you close the app and check that it isn't running in the background through task manager then you will not have ads running. If you want to play games on it, run lots of apps, use GPS, etc then you can expect the battery life to shorten. I think the report is a bit harsh on ads but ought to be pointing out that perhaps if they used the phone as smartphone and not a toy it might last longer.
I can kill mine inside 1hr by using satnav,listening to music online etc,or I can turn off everything & get 6 days or longer.I would love to uninstall most of its apps,only they came pre-installed on it & as a result I have to leave WiFi on at home so they can chat with whoever through my router & not use up my bandwidth.
I get two days out of my HTC Desire S before it starts complaining that the battery is low, although I rarely hammer it.
A couple of months back I left my phone on my desk at work on Thursday, and wasn't back in until the following Wednesday, it was still switched on, but had automatically shut down everything except the cellular receiver.
My niece has recently acquired a Blackberry and needs to charge every day,her I phone is, in contrast, long life.My old C905 was every day,my present W995 every 3 days,when on internet every day.So battery life does depend on usage as Chegs says.
I'm not a smartphone user but it occurs to me that this used to be (still is for me) a frequent topic of discussion for new adopters of laptops a few years back when they became an affordable alternative to a desktop machine.
Stemming from that I think an obvious suggestion is to turn the screen brightness down if possible.
We just did a straw poll about smartphones and tablets in the office. We have an average of two of each, each (occupational hazard) and very few of them last a whole day in use. My iPhone 3GS, for instance, can barely scrape through a working day without a recharge, but then (a) it is old and (b) I listen to music on my walk to the station, manage my email almost entirely from my phone as I travel to and from work, and use it pretty constantly to check the site, check the site analytics, post to Twitter/Facebook etc. If I was using a laptop for the same tasks I'd be amazed to get beyond three or four hours. And, intriguingly, my Samsung Galaxy Tab 10.1 and BlackBerry PlayBook both last a lot longer, even under the same strain. Bigger screen and device, but also a much bigger battery.