Commerce is bonus energy generated from trade between two friendly factions. Whenever you sign a Treaty or Pact with another faction, your bases will automatically begin to accrue commerce (and this benefit extends to your partner faction as well).
Commerce is interrupted whenever a Vendetta occurs between two factions, or when sanctions are applied against afaction which has committed an atrocity. Think of Commerce as a reward for peaceful behavior.
Between two factions, commerce is more beneficial to the faction which has discovered the most Economic technologies. CEO Morgan gains additional bonuses here as part of his faction power. Commerce also tends to benefit the current Planetary Governor.
You can increase your commerce rates by doing the following:
* Sign more Treaties.
* Sign more Pacts (Pacts receive double commerce).
* Increase the size and economy of your bases ("it takes energy to make energy").
* Discover more economic-related technologies
Economic related technologies include Industrial Economics, Industrial Automation, Planetary Economics, Industrial Nanorobotics, Sentient Econometrics, and Environmental Economics.