People's attention are limited. Grab it quickly and wisely

• Be focus (use the right medium to deliver your message to the right people, at the right time). Try to pick the time that they first think 'bout the needs of your products and tap into it (married woman might not want to buy children clothes but if you talk 'bout it right after they're pregnant, they do want to hear)

• Can do this even with demo product, no need to wait until final production. This also helps to gauge the demand of your product and modify if needed

• Tell them 'bout the value proposition of your product (what's in it for them, which problem it will help to solve) rather than just merely the features

• Framing. You can somehow selectively pick what you will tell your customers in order to get them focus on your strong points. Note that there is a fine line between this and "cheating"

• Get a catchy (simple, one-line) slogan

• Ask for their permission to continue telling 'bout the products afterward

• Let them try it. If they just look at it, they will consider many factors ("this might be of good quality, but what 'bout the price then ?"). However, if they use it and "get" the benefits, their concerns will greatly reduced

• Educate your customers. This will build their trust for you, as well as let them fully appreciate the value of your products (rather than just the cost-factor of it)

• In some cases, (small) free gifts can grab people's attention. Everybody like something free.

• Use narrative (testimonial). People tend to believe more when they read 'bout experiences of others who tried it before.

• Build reputation. People can pay a premium for that.

• Get in (positive) controversy

source: this book (highly recommended) and my personal experiences