"Those of you with existing applications should add a canvas view to take advantage of more screen real estate. And using canvas view, you can also monetize with ads," said Dan Holevoet of Google's developer programs group, on the blog.
It won't be an ad free-for-all, though.
"Ads will be limited to the canvas view only and certain types of ads will not be allowed. Developers are free to use any ad provider," said iGoogle senior product manager Jessica Ewing in a statement. "To maintain the best user experience, we plan on surveying users to determine how ads impact user satisfaction. Poor user ratings and reviews may impact a gadget's viral features, ranking, and directory listing."
And Google wants to be sure ads aren't inadvertently clicked, a problem in the regular non-canvas view. "We don't allow advertising in the home view (small gadget view) because the gadget real-estate is limited and we've noticed that many clicks in that space are in error," Ewing said.
Also coming later this summer are iGoogle updates and notifications, where for example an application can notify a user's friends of some event such as a new high score in a game.