League of Legends (LoL) Item: Explorer's Ward

I use it to keep track of the enemy support or drop it in a bush or intersection during a teamfight to be warned of incoming or hidden champions.

Its useless, but just compare it with the 20 Startgold Masteries, 20 Gold is 4/15 Ward, which are 48s, there is the Wardmasterie better. I often use it to see the enemy support for 1minute camping

Could anyone tell me the proper use of this? 60sec is quit short imo to us it in real battle.
At the moment I'm putting it somewhere almost before the minions spwan to prefent enemy stealing the jungle.