It is a well known fact that promotional messages hidden inside actual content actually pay off better than explicit banner or pop-up ads. Without looking into issues relating to ethics over the various forms of advertising, a study from AdFusion looked into the likelihood of consumers to act upon these various advertisements. Interestingly, the ad formats have been increasing in effectiveness over the past year.
Here are the percentages of consumers who have acted upon the promotional messages this year. The corresponding number for 2009 is given within brackets.
Articles including brand info : 53% (51%)
Email Offers : 51% (47%)
Sponsored Search results : 40% (39%)
Banner ads : 28% (25%)
Pop-up ads : 19% (13%)