Garnier's UltraLift

This is an advert for anti-wrinkle cream, which uses multiple sources as its main method of persuasion. It shows a number of women all talking about why they liked the product, and how successful they found it to be at reducing their wrinkles. Using multiple sources to deliver a congruent message was found to be more effective than one source delivering the same message (Harkins & Petty 1981).
Harkins and Petty (1981) showed videos of either 1 or 3 speakers, delivering either 1 or 3 persuasive messages, and found that the condition in which 3 speakers delivered 3 messages produced significantly higher results on an attitude questionnaire.

Another tactic that was employed was the similarity altercast, which is when the source of the message is similar to the person receiving the message. In this advert this is achieved partly by using phrases such as ‘women all over the uk’ and ‘over 25000 of you’, which imply similarity, but also by showing ‘real’ middle-aged women being interviewed in their homes. This was shown to be a successful way of increasing influence by Brock (1965), who  found that paint salesmen were more successful if they had previously performed a job similar to the person they were selling to.

  References

Brock, T. C. (1965). Communicator-recipient similarity and decision change. Journal of Personality and Social Psychology, 1,650-654.

Harkins,  S, G., & Petty, R, E. (1981). Effects of source magnification of cognitive effects on attitudes: An information-processing  view. Journal of Personality and Social Psychology, 40, 401-413.