I remember from some hear-say at the hydro shop that there was some legal issues with it's label when they tried to call it an organic pesticide. I don't remember the details but some way some how they just changed the products description as a "leaf shine", confident that shop owners and consumers already knew the effectiveness of it's insect control. This is now my sole weapon of mass destruction against the destructive insect populations that dare to invade my territory. It's all I need for the fight against plant terrorism. A few applications during early veg phase will keep everything away up until harvest. It's a real good product.
You will need to use a wetting agent to help break down the oil concentrate when you dilute the mixture. I use my Dutch Master "Penetrator" that is used in conjunction with Dutch Master "Liquid Light". The Penetrator is a very sophisticated wetting agent and works very well breaking down the neem oil into water. This bottle cost me around $20 and lasted a year. I got mine at my local shop but Sunlight Supply carries it as well. I give all of my plants multiple applications in early veg so I use a decent amount and I think it's well worth the twenty dollars. Be well...