Do art galleries sell? (Roberto, Manuel)

by Roberto
(Rome)

Since 3 years I cooperate with 3 galleries. Cooperation means that I pay an annual fee and participate in some exhibitions and art fairs. The galleries never sold anything. I asked some colleagues, who also have their works in some of these galleries. Same thing. All 3 galleries meant I had good chances to sell and they chose me because my art is interesting and has good possibilities. Why they don’t sale? Is anything there that I don’t understand? Can somebody explain me what is happening?