First-order effects

• Microsoft Exchange customers evaluating Google Apps lose their main practical objection — the cost and disruption of moving years of email, calendar, and contacts — because a single server-side tool now does the migration rather than desktop-by-desktop work.
• Google's sales motion shifts from convincing buyers Apps is viable to making the exit from Exchange administratively trivial, directly attacking the switching cost that anchored Microsoft's enterprise messaging base.

Second-order effects

• Microsoft faces pressure to respond on its own hosted-mailing economics — when leaving Exchange gets cheaper, Exchange's pricing and hosting terms become the battleground rather than its feature set.
• IT integrators and resellers who made money on bespoke Exchange-to-cloud migrations see that line of work commoditized into a vendor-supplied tool, pushing them toward advisory and deployment services around Apps instead.

Third-order effects

• If migration keeps getting easier, competition among office-productivity platforms turns on post-switch factors — administration, reliability, and add-on ecosystems like the Marketplace — rather than on data-portability lock-in.
• The pattern points toward enterprise software judged by exit cost: vendors that make leaving expensive retain customers even against better products, so lowering switching costs becomes a competitive weapon for challengers across business software, not just email.