Do your CRM, CMS, ERP, etc systems “talk” to each other? If a customer calls up do you have one interface to see their entire history? Even with the profiliferation of affordable, high-quality systems like Salesforce.com, Pardot, and Parature, most companies don’t have a way to see the history of interactions with a client from one screen. Typically, companies also have custom spreadsheets or applications where related customer information is kept, in an even more siloed fashion.
One major benefit typically found in true SaaS systems (not fake ones) is that of an open web services API (typically SOAP or REST). An open API, and a system that isn’t in your own private network (who wants to keep ports open in their Firewall?), is a good recipe for integration. More companies should invest in consolidated systems as part of a larger strategy to divest of non-core IT functions (like CRM and CMS).