Nobody will replace CPC for CPM, unless you are clueless..

[asianguy]

If you are a publisher, you would not choose CPM over CPC. Look around for those companies that are doing CPM, where are they now?

[alika]

It really depends on your topic. As we see here in the forum, some websites do very well with CPC. But there are sites who are not doing as well with CPC since their visitors are not really looking for anything other than the site they visited (e.g. news portals, entertainment sites, etc). Many of these sites do well instead with the CPM models, particularly those with large amounts of traffic. When you visit forums of ad networks, for example, you will find many sites who swear off Adsense (the CPC model) as totally useless for them, but generates tremendous income from CPM models. These are the same sites who will welcome this new development

[jomaxx]

As long as advertisers are paying an equivalent CPM to what a CPC ad would earn in its place, I don't see a problem with this in principle.

My main concern is that the whole CPC vs CPM balancing process will be another black box hiding an immensely complicated algorithm -- leading to ever more confusion about how ads are matched and ever more suspicions that Google is maximizing its own revenue at the expense of its partners.