Adverts. Nobody really likes them, especially those foreign ones that get badly re-dubbed in English. On your mobile they can, according to a report picked up by the BBC, suck a lot more battery life too. By running constantly in the background and offering “helpful offers and reminders” some advertising systems can consuming 75% of the energy required by the app itself.
The research, which has been conducted by Purdue University and Microsoft Research, strangely concentrates on Android and, of all things, Windows Mobile. One can only assume that the Microsoft Research guys didn’t want to dampen any enthusiasm for Windows Phone.
The team looked at Angry Birds – an app not available for Windows Mobile – and found that only around 20% of the battery consumption was used by the app itself. From the remaining power, 45% of it was used by GPS just to provide location-specific ads. A bucket load of power is consumed by feeding data back to servers about location.
So, if you can, turn off GPS, turn the backlight down and sit in a dark room.