Oracle sells alot of software that is accompanied by hordes of consultants to set it up.
Last F50 I was at did a PeopleSoft migration. We probably had 400 Oracle employees pass through the doors over 2 years helping to get it off the ground.
Most Enterprises don't just buy software and that's it. They buy software + support to implement it for their business.
plus yearly support maintenance
Sure but what did those guys do all day? 400 people is a lot of people