Airbnb's AI-driven party prevention is a pro-host move to counterbalance recent pro-guest changes to its fee structure. This illustrates how platform businesses must continuously alternate which side of the marketplace they favor to keep both groups engaged and prevent churn on either side.

Consumers are inherently skeptical of perfection. A flawless 5.0 rating can feel inauthentic. A slightly lower score, such as a 3.8 or 4.2, is often more trustworthy as it signals a real, un-manipulated customer base. Businesses should embrace and showcase realistic scores starting from 3.5.

Humans evolved to cooperate via reciprocity—sharing resources expecting future return. To prevent exploitation, we also evolved a strong instinct to identify and punish "freeloaders." This creates a fundamental tension with social welfare systems that can be perceived as enabling non-contribution.

The fear of loss is stronger than the attraction to gain. This "loss aversion" explains why people hesitate to initiate positive gestures, like smiling at a stranger in an elevator. They are willing to sacrifice an almost certain positive reciprocal outcome (98% chance) to protect against a tiny risk of looking foolish (2% chance).

Tipping creates an 'economic surplus' because consumers mentally discount its cost (a $1 tip feels like 80¢) while couriers inflate its value. This inefficiency gives tipping-enabled platforms a competitive advantage, making the feature almost inevitable for any delivery app to maximize revenue and compete effectively.

Most people only review products they love or hate, creating a J-shaped curve of extreme opinions. Prolific reviewers are less prone to this self-selection bias, as they review more consistently. Their ratings provide a more balanced and trustworthy distribution of opinions.

Perfection is often perceived as 'too good to be true', leading consumers to suspect that negative reviews have been removed. A Northwestern University study of 100,000 reviews found a tipping point, typically between 4.2 and 4.8 stars for FMCG products, after which purchase likelihood begins to decline. An imperfect score is more believable.

Travis Kalanick claims delivery app tipping isn't about service feedback but is a tool to maximize consumer price. He posits that consumers are economically irrational, perceiving a $1 tip as costing only 80 cents, while couriers perceive it as being worth $1.20. This psychological gap creates an economic surplus that competitors can exploit to gain market share.

The success of services like Uber isn't just about saving time; it's about the *perception* of convenience and control. A user might wait longer for an Uber than it would take to hail a cab, but the feeling of control from ordering on an app is so powerful that it overrides the actual loss of time. This psychological element is key.