If customers are asking to pay for your product before it's available, that's a strong sign of traction.

The hardest part of a startup is getting from idea to traction, which is often where most companies fail.

Good traction is often measured by growth rate; showing significant growth in revenue is more impressive than having a static revenue figure over time.

Many people mistakenly believe that traction or revenue is necessary to apply to Y Combinator, but that's not true; a significant portion of funded companies only have a founding team and an idea.

Real startup progress is defined by tasks that genuinely move the needle, such as growing your primary key performance indicator (KPI), which is typically either revenue or active users.

If your startup has strong network effects, focusing on active users may be more important initially, with revenue becoming a focus later on. It's crucial to define what 'users' means for your startup, as it can vary significantly. For example, having 100 users could mean they just signed up or that they actively engage with your product daily for about 10 minutes. The latter is a much more valuable metric.

To succeed in a startup, you must create something that customers want to buy, which often involves creating tension that drives them to act.

Startups require active marketing; having a great product alone won't attract users unless you actively seek them out.

If you're going to charge for a product, it needs to be self-serve and frictionless for users. Many startups fail because they rely too heavily on founder involvement for customer acquisition.