> 18. Fees. Provided that Google continues to offer the Service to Customer, Google will continue to provide a version of the Service (with substantially the same services as those provided as of the Effective Date) free of charge to Customer; provided that such commitment: (i) does not apply to the Domain Service described in Section 4 above; and (ii) may not apply to new opt-in services added by Google to the Service in the future. For sake of clarity, Google reserves the right to offer a premium version of the Service for a fee. [1]

[1] https://web.archive.org/web/20110429023658/http://www.google...

Of course, Google later removed this clause from the ToS.