There's plenty about the travel industry that I wouldn't wish on my worst enemy. Hotels struggle with diminishing margins, airlines face the constant threat of restructuring, and rental car companies barely earn a return on quickly depreciating assets.

Yet there's one aspect of that industry that is the envy of every retailer I know. Do I even have to name it? I'm talking, of course, about travel loyalty programs.

For over 30 years, the travel industry has been successfully designing incentives that turn occasional customers into loyal patrons. Penetration is sky high, as is engagement. Elusive silver, gold, and platinum cards remain highly prized, offering clearly articulated, valuable benefits, such as upgrades, airport club admission, and priority boarding. The triumph of travel loyalty programs has made their currencies valuable and omnipresent. In 2002, when Air Canada spun out its Aeroplan loyalty program as a subsidiary, it was worth more than its parent. Today, even your choice of cable TV provider can be affected by mileage rewards.

But while travel companies figured out long ago how to convert loyalty from a cost center into a revenue driver, many retailers, in comparison, have barely achieved loyalty liftoff. Most do little more than award points for dollars spent, with few efforts to prompt incremental purchases. As a result, they're basically forfeiting a percentage of their margins to their best customers while creating ever-increasing liabilities on their balance sheets.

I believe there's hope for retail loyalty. But retailers will have to step out further from their comfort zones, and one way is to capitalize on the many profound loyalty lessons of the travel sector. The great news is that implementing even one of ideas will have a direct positive impact on the lifetime value of your customers.

1. Make status truly desirable
I'm amazed when retailers think exclusive offers alone will motivate someone to strive for premium status in their loyalty programs. Can you imagine if United Airlines, instead of complimentary upgrades, promised to dole out more advertisements to its best customers? If you're an omni-channel retailer, create an exclusive cashier queue, designate easy-access parking spots, and offer free alterations. For your absolute best customers, design an invite-only status tier with a personal shopper. (For inspiration, look at Harrods.) Pure-play ecommerce retailers should invite members to special events and provide exclusive early access to hot products.

2. Make rewards more exciting than discounts
Straight discounts are, frankly, boring. And gamification can feel forced, if not downright tacky. Travel companies are great at offering redemption options that are truly attractive. For example, Starwood Hotels offers fixed redemption rates for rooms regardless of market price, so customers excitedly look for ways to earn and burn. Retailers can offer certain product lines exclusively as redemptions. In addition, access to sales before they happen, or tier benefits (such as a personal shopper) could excite some customer segments. According to Howard Schneider, partner at loyalty consulting firm Metzner Schneider Associates, the right rewards can be far less costly than discounts. "Rewards can have greater perceived value than actual cost-what we call reward leverage," Schneider says. "Pure discounts cannot be leveraged."

3. Expand reward opportunities through partnerships
Most consumers won't spend enough with one retailer to justify rewards of much value. Travel industry companies pioneered the solution to this problem through partnerships that add earning and redemption opportunities. For example, Hertz today allows you to earn its GoldPlus Rewards through most airlines and hotels, and vice versa. While retailers have a longer way to go here, we're already seeing partnerships like those between Kroger and Shell, and Safeway and Chevron. Large retailers could also gain by consolidating the loyalty programs of subsidiary brands, as 1800Flowers.com has done. Eventually, numerous non-competing retailers could link together their programs with one compelling currency, as airlines have done through loyalty alliances.

To be sure, travel and retail are different beasts. Travel companies are blessed by a significant base of near-price-ambivalent, frequent customers (business travelers) and the industry has many pain points that loyalty can mitigate, including long lines, claustrophobic seating, and frequent delays. But as loyalty guru Schneider points out, the real strength of a well-designed program is much more than rewarding top customers. "An effective program," he says, "enables marketers to identify, incentivize and reward customers with incremental potential."

For retailers looking to deliver on that vision, the travel industry is a great place to look for inspiration.