NY Times article on particulars of how Google GMail will work.  Of special interest re: trademarks:

Interestingly, Google has decided to allow e-mail messages sent by businesses promoting their services to contain ads from competing companies.

Last week, an e-mail message sent by Citibank to one customer, for example, arrived on Gmail with ads from Citibank and two financial services groups: National InterBank and Lots-of-Credit-Cards.com.

This kind of rival advertising has been a contentious issue on Google’s Web search service. American Blind and Wallpaper Factory, for example, has sued Google demanding that it not show ads from other blinds sellers when people search for its name. Ms. Wojcicki said that Google believes that presenting ads from a range of companies is a service to its users.

Update:  I’ve spoken to some colleagues about this.  One reaction – some direct marketers’ response will likely be to purge their lists of GMail addresses precisely because of this.

I’m hesitant to comment on something I’ve never seen (I’m going to sign up today) – so consider the following to be speculation unfettered by empirical knowledge.  When I receive my credit card statement from XYZ, and the envelope contains various ad inserts, I don’t necessarily assume that the advertisers are owned by XYZ but I do assume that XYZ approved the placement of those inserts in some way (and if the advertiser turned out to be fly-by-night, it would, at a minimum, refect poorly on XYZ).  If the advertised goods or services were identical to those provided by XYZ (for example, credit card services), that fact would strengthen my belief that there was a relationship.  After all, it’s hard enough to get your customer’s undivided attention. I assume that GMail will disclose to its users that the advertisers are unrelated to and unsponsored by the sender of the email.  Will that disclosure be powerful enough to offset the common belief that companies tend not to provide advertising opportunities to their competitors?