What was the effect of Greek colonization in the Mediterranean?

The most practical benefit or effect of Greek colonies throughout the Mediterranean Sea was the supply of food and other material to the city-states of the Greek mainland. Mainland Greece is not well suited for farming because of the rocky geography, so Greeks set out to the seas to find arable land. Obviously, the colonies supplied goods to Greece that would not have otherwise been available.

Despite the practical purpose of the colonies for food...

The most practical benefit or effect of Greek colonies throughout the Mediterranean Sea was the supply of food and other material to the city-states of the Greek mainland. Mainland Greece is not well suited for farming because of the rocky geography, so Greeks set out to the seas to find arable land. Obviously, the colonies supplied goods to Greece that would not have otherwise been available.

Despite the practical purpose of the colonies for food production, the colonies had the effect of spreading Greek culture and ideas throughout the Mediterranean Sea. In this way, Greek commerce, art, language, and political innovation was spread to Spain, France, Italy and North Africa.

The most successful of the colonies, primarily due to its central location in the Mediterranean, were those on the Italian peninsula. Greeks in Italy were very successful and came into contact with people from the north on a regular basis. In this way, the Greeks influenced the development of Rome.  The Hellenic influence on the future Roman empire cannot be overstated.