The average cost per 1,000 views (called average CPM) for an advertiser running ads with online videos is below. Remember these average video CPMs are what the advertiser pays, the publisher may make far less.
Average CPM for Premium content, broadcast content online: $21-$30
Average CPM for Mid-Tier, professionally produced content: $11-$20 Average CPM for User Generated Content: $0 - $5
(from Online Video Ad Budgets Expected To Rise Sharply In 2012). The video owner definitely makes less if there is an ad broker making the deal happen, like Google AdSense on YouTube.