It’s hard to do justice to Influence: The Psychology of Persuasion by Robert Cialdini in a few words, except to say that is very likely the best book on sales ever written.
Cialdini identifies the six major tools of influence (i.e. sales):
- Social proof;
- Authority; and
On reciprocation: Giving gifts—even very small ones—creates a major sense of obligation in the receiver to reciprocate. Often, they will jump at the chance to get rid of that perceived obligation. The takeaway for salespeople: Give small “free gifts” before making the big sale. Or, ask for something big first, then retreat to something smaller when they say no, so they feel they owe you the sale.
On consistency: People have, and want to have, a strong sense of personal identity. If a potential buyer is “primed” beforehand to identify with your product, they’re much more likely to go all the way with it. The takeaway for salespeople: Get potential buyers to identify with your product in some (seemingly voluntary) way, such as agreeing to write a letter, sign a petition, display a small sticker or logo, pass along an email, etc. This also creates a perceived commitment, which they are loathe to go back on later. Or, get someone to commit to a product by making a lowball offer, then raise it later.
On social proof: People copy each other. They just can’t help it. No one can do all the research themselves; they rely on others to lead the way. The takeaway for salespeople: Use the cliché pitches: “fastest-growing,” “most popular,” customer testimonials, etc.
On liking: Liking is also a super effective way to encourage the desire to buy. The takeaway for salespeople: Think about how can you get people to like or root for your brand—to be on your side, identify with your cause, want to spread the word.
The book also discusses the principle of contrast, saying that when you first try to sell a higher priced item, or you artificially raise the price to begin with, when you take it down a notch it feels like a great deal.
Get the entire recommended reading list at Books I Want My Kids to Read Someday.