What should I put on a postcard to generate calls?

To generate immediate phone inquiries, print a direct-mail postcard featuring a bold headline identifying a specific problem, an exclusive time-sensitive offer, a dedicated tracking phone number in 28-point type, and three clear trust proof points.

Direct mail delivers average response rates between 2.5% and 5% according to Association of National Advertisers benchmarks, yet promotional mailers frequently underperform when overloaded with text. Service providers and businesses lose inbound calls when prospective customers cannot identify the core offer, service area, and primary contact method within three seconds of handling the card.

If you only do one thing: Place a high-contrast, dedicated local phone number formatted in at least 28-point bold font alongside a deadline-driven promotional incentive visible on both sides of the card.

• Problem-focused headline: State the core service and target city in 10 words or fewer using a 36-to-44-point sans-serif font to establish clear relevance within 3 seconds of scanning.
• Direct financial incentive: Feature a specific discount, such as a $50 to $250 project credit, paired with an expiration date set strictly 21 to 30 days after the mail drop date.
• Dedicated call tracking: Assign a unique 10-digit tracking phone number to the mail drop to log call volume and calculate return on investment per 1,000 pieces delivered.
• Trust credentials: Display verifiable trust markers, such as a state license number, trade accreditation, or a documented 4.8-star rating summary across 50 or more verified reviews.
• Substantial paper stock: Print commercial postcards on 14-point or 16-point coated cardstock to maintain structural rigidity during automated postal sorting without folding or tearing.
• Balanced negative space: Reserve at least 35% of the total layout surface as unprinted white space to maintain readability around the contact number and headline.

• Watch out for: Listing 3 or more competing contact channels, such as website URLs, multiple email addresses, and social handles, which dilutes phone response volume.
• Watch out for: Using lightweight paper stocks under 10-point cover weight (approximately 200 GSM), which can bend in transit and fail minimum carrier durability standards.
• Watch out for: Placing artwork inside the required 4-by-2.25-inch postal clearance zone on the bottom right of the address side, which risks delivery rejection by automated sorting machines.

Select target ZIP codes or carrier routes, then order a pilot run of 500 to 1,000 postcards on 14-point stock with your dedicated phone line before launching full-scale distribution.