This adverts by First Plus uses source credibility as a persuasive technique. Carol Vorderman, who fronts this advert, is a celebrity well-known for her mathematical expertise. In this advert she suggests that taking out a first plus loan is a cost effective way of managing your finances. For example, “When you look at the sums you will see how much better off you can be each month” and “a sensible secured loan.” The idea behind this is that viewers will trust her ‘expert’ claims and in turn are more likely to take out the loan.
Research by Hovland and Weiss (1951) provided evidence that source credibility increases believably of a message. They demonstrated that participants were more likely to believe a message if it was presented by an expert compared to a non-credible source. Moreover, in a study by Ohanian (1991) the perceived expertise of celebrity endorsers’ explained the subjects’ intention to purchase endorsed products. In this study participants were shown a celebrity endorsing a product, and then had to rate the source credibility of the celebrity and their likelihood to inquire about, consider purchasing and actually purchasing the celebrity endorsed product. It was found that the higher the perceived celebrity’s expertise the higher the respondents' intention to purchase the product.
Hovland, C. I. & Weiss, W. (1951). The influence of source credibility on communication effectiveness. Public Opinion Quarterly, 15, 635-650.
Ohanian, R. (1991) The impact of celebrity spokesperson’s perceived image on
consumers’ intention to purchase. Journal of Advertising Research, 31(1), 36–52.