Well technically Google seems to be sharing revenue generated from services like Search, Gmail, Maps, etc. with their carrier and manufacturing partners to incentivize their "going Android". If rumors of Apple making a cool $100,000,000 a year from Google for iPhone search are any indicator, the money may be nothing to sneeze at either.
Apple by contrast also gets $400 from AT&T per iPhone customer (the part AT&T subsidizes off full list price so those who sign contracts can get the iPhone 3GS for $199 instead of $599). So Apple is making money, Google is paying money (offsetting manufacturer cost), but the revenue -- and the access to Android users' data -- is likely so valuable to Google that they consider it well worth the investment.
Given how many and how fast new uber-Android devices are hitting the market, the carriers likely don't mind one bit. (Android aficionados who just bought the Nexus One and now want the EVO 4G, on the other hand, might prefer a bit of a breather.)
Either way, both companies are so obscenely profitable that their respective business models must be doing something right. Still, it's interesting to see the differences in those business models. RIM tries to sell their small network footprint, Apple their brand cache, Google their free OS with revenue sharing services. Which one will prove most successful? We'll have to wait and see.