Well surprisingly Summoner still is a DoT based Job even though its got a LOT more Direct Damage attacks these days once you pass level 60.

One of them is a DoT you don't even think is a DoT but actually is... the Egi.

The Majority of a Summoner's damage even today is the Egi + DoTs. The rest of the Summoner's damage is all stacked on top of this. So... if you just keep those two things running all the time, it will be the lion's share. As its the basis upon which all other Damage is stacked.