Cosmoprof is a beauty supply store specifically for licensed or apprenticing hairstylists/estheticians. They are not open to the public because they carry supplies that can be hazardous and harmful if not used by trained professionals. They carry several hair colour lines that are popular in salons such as L'oreal Proffesional, Wella, Rusk etc. at a price that is just above cost. For that reason alone they are closed to the public. If clients could colour their own hair for cost it would take away from the trained professionals that rely on these services for income. You can also find a variety of salon use only hair products, OPI nail polish and a variety of esthetics supplies.
In fairness to the other reviews, the woman that work at the 2 Cosmoprofs that I regularly frequent (Main & Danforth/Markham & Progress) are always very rude. They have extremely poor customer service skills and always act like you're bothering them. I have been going to the same 2 locations for 5+ years on a regular basis and most of the time when I walk in (Main & Danforth especially) they bark in such a snotty tone "Do you have a membership?!" I can see how that could be embarrassing and off putting to those that don't have a membership... I find it embarrassing and I DO have a membership.
I love Cosmoprof. It is really convenient to have around especially to make some money on the side but they lost 2 stars because of their rude customer service.