Internet Retailer writes that some concerns about Google's impression-based CPM ad effort, announced two weeks ago, are subsiding. Google's CPM program, in beta, allows advertisers to bid on price per thousand impressions and target display ads to specific affiliate sites; it seemed tailored to deep-pocketed advertisers centered on brand awareness. But after absorbing program details, search marketing experts and some internet retailers apparently now say the new program does not necessarily pose a threat to internet retailers with modest ad budgets; for example, they would be able to run banner ads on the same affiliate sites as the bigger players, albeit in a lower position.