Cost per thousand (e.g. CPM Group, Advertising.com), also known as cost per mille (CPM), uses pricing models that charge advertisers for impressions — i.e. the number of times people view an advertisement. Display advertising is commonly sold on a CPM pricing model. The problem with CPM advertising is that advertisers are charged even if the target audience does not click on (or even view) the advertisement.
In marketing, lead generation is the initiation of consumer interest or enquiry into products or services of a business. Leads can be created for purposes such as list building, e-newsletter list acquisition or for sales leads. The methods for generating leads typically fall under the umbrella of advertising, but may also include non-paid sources such as organic search engine results or referrals from existing customers.