I have been using Airwicj Freshmatic since it came out and I really enjoy it. If you just starting out, you would want to buy the starter kit which come with the automatic unit, 1 fragrance spray, and 2 batteries. There is another button that you can use just in case you want to spray your room before the timer goes off. You can hang it on a wall or put it up high so that no one notices it. You can set the unit to spray every 9, 18, or 36 minutes. I usually set mine for 36 and I find by doing this it usually last about 60 days. Airwick usually makes the replacement sprays that usually cost about 3.99.
I find this product is easy and convenient because I dont have to hold a spray can as it will automatically dispense the fragrance based on when it is set. The fragrances are light, and is great for any room.