Asphalt shingles come in two basic types: fiberglass and organic. Organic shingles contain around 40% more asphalt than the fiberglass alternative, which makes them weigh more and gives them excellent durability and blow-off resistance.
The more popular shingles are the fiberglass ones. This may be because they are cheaper and easier to manufacturer than organic shingles, making them more cost effective for the homeowner.