You'll notice me talking about the "Comedogenic Rating" that all oils have. Comedogenic simply means the ability for the oil to clog your pores. Ratings start at 0 and go through 5. The higher the number, the higher chance you have of the oil clogging your pores. Using a non-comedogenic oil means that oil will not clog your pores. Acne and oily prone skin types should be using oils that have a 0-1 rating, anything higher and you may run the risk of clogged pores and more breakouts. Normal/combo skin types should be able to use oils with ratings of 2-3 and dry/mature skin type should be able to use oils with ratings up to a 3. When discussing products for your face and neck, these ratings seem to matter a bit more, however listen to your skin, it's your largest organ...feed it what it loves!
**Keep in mind, these are ratings, not hard and fast laws! Everyone's skin will react differently. Some people can use ingredients with 4's and not have an issue at all (my faves have always been 4's and 5's!). Whatever you do, don't just use products because they're popular or because they were free...stick to what it loves! :)