I suspect that all ad-revenue sites are subject to the same economic pressures. Almost all such companies eventually succumb to these pressures.

All such companies will tend to cater to the lowest common denominator. They will tend to put their own interests (that of showing ads and increasing ad effectiveness) over the interests of users.

Perhaps there is an opportunity for a paid integrated search/email/calendar/reminders/maps/events application? You pay them $5 or $10 per month, and they do their best to create the best possible experience for you. Apple and Microsoft are well positioned to become this company as well, as is Google.

Wouldn't it be ironic if Yahoo! became this company?