How we change what others think, feel, believe and do
Rather than make a standard request for something, make an unusual request that leads people to wonder why you are making that particular request (and hence pay attention to you).
If they ask you why you are asking for something novel, then you can engage them in other methods of persuasion.
Santos, Leve and Pratkanis (1994) got a 'panhandler' beggar to ask passersby for money. In the control conditions, when they asked "Can you spare any change?" 44 percent of passersby complied. When they asked "Can you spare a quarter?" the compliance rate increased to 64 percent. When they asked "Can you spare 17 cents?" or "Can you spare 37 cents?" about 75 percent of people made a contribution.
Ask to meet people at seven minutes past the hour, rather than on the hour.
Making a novel request creates surprise, breaking the person out of their schema and forces them pay attention, thinking further about your request in a central processing fashion. The novelty in the request piques their interest (hence the name of the technique).
Note that you do not always want people to think too hard about what they are being asked for. In such cases, the reverse process should be used, asking for a common thing and not something that will pique interest.
One reason why Santos et al's panhandler experiment worked was that When walking past a beggar, people try to be 'unthinking', not noticing them, as they remind people of unpleasant possibilities that 'could happen to anyone'. The Pique Technique forces them to think and hence act.
In a later meta-analysis, Lee (2017) reviewed six studies and confirmed that seeking donations earned more, not because the pique technique gained more money per donation, but because it increased the chance of getting any donation.
Santos, M., Leve C., & Pratkanis, A. (1994). Hey buddy, can you spare seventeen cents? Mindful persuasion and the pique technique. Journal of Applied Social Psychology, 29, 755-764.
Lee, S. (2017). A meta-analysis of the pique technique of compliance, Journal of Social Influence, 12, 1, 15-28