* Eloqua is a robust system that can handle a huge contact base.
* Allows automation of almost any process, from emails to landing page submission to tracking contact activity in Salesforce.
* The Eloqua user community (called Topliners) is lively and helpful.
* Integration with Salesforce works well (though it takes a lot of setup).
* App plug-ins (called Cloud Connectors) to extend functionality even further.
* Lost functionality in E10 (newest version) -- some of the more complicated tasks in E9 have been dumbed down in the service of making the interface more user-friendly. Several out-of-the-box reports are no longer available.
* Technical Support can be hit-or-miss; online documentation seems to have decreased in favor of pointing people to the online community for answers.
* Use of email address at the primary contact database key leads to some complicated work-arounds for us.
* E10 is buggy compared to E9, despite having been out for more than a year.
* Decide what you need out of a marketing automation system. If you're just sending emails and logging recipients, Eloqua would be overkill. If you want to do lead scoring, campaign automation, etc., then you should consider Eloqua.
* Have dedicated resources (both time and money) for post-launch. A healthy system requires at least one full-time admin, and I would suggest a few training licenses for power-users.