There are lots of ESPs. Some have a particular focus on specific vertical markets. Others focus on offering more than just email and become integrated marketing solution providers. Still others are leaders in social email marketing. And there are those whose email marketing platforms become marketing automation platforms.
You have local players and regional players. And then you have those that don’t think local or regional but global.
Competition is increasing in this last category. The battle of the big ESPs seems to be partially a battle for global expansion and a presence in the main markets.