Stay twice, get one free. That's the basic come-on in the latest promotions from two major hotel loyalty programs, Starwood's Preferred Guest and InterContinental's Priority Club Rewards.

At first glance, the offers might appear indistinguishable. But the fine print reveals that the offers are far from identical. And the differences highlight five critical considerations in assessing and comparing any hotel loyalty program promotions.

Qualification criteria: Both promotions promise a free night after two stays. But where Starwood awards a free night after two paid stays, Priority Club does so after two paid nights, whether they're consecutive or not. Of course, a stay can be as short as a single night, in which case the bonus can be earned after two nights in either promotion. But Priority Club's hurdle — two nights versus two stays — will be lower for most travelers.

On the other hand, where Starwood customers earn the free nights in addition to their regular points for qualifying stays, the Priority Club bonus is in place of their normal earnings.

The decision: Split. It will be easier to earn the free night with Priority Club, but travelers will forgo their normal points to do so.

Rewards: While a free night is the featured reward in both promotions, there are significantly different restrictions on redemption of the awards.

Starwood's free night must be taken over a weekend, for a Friday, Saturday, or Sunday night stay. And the freebie must be redeemed by Sept. 30.

The Priority Club free night can be taken on any day of the week. And the deadline to use the free stay is Dec. 26.

Not interested in a free night? Deep in the terms and conditions of the Priority Club offer is this reference to an alternative promotion: "Members ... may alternatively choose to participate in earning double points or double miles and will be prompted to choose which promotion they prefer on the registration page for this Promotion. Members may only participate in one of these promotions."

That's right, during the same period, Priority Club members can opt instead to earn double points or miles for the second and subsequent stays at InterContinental, Crowne Plaza, Hotel Indigo and Holiday Inn hotels, and for every stay at Staybridge Suites and Candlewood Suites hotels.

With more flexible rewards, and an alternative offer to boot, Priority Club is the easy winner in this category.

Reward caps: For those who are true frequent travelers, an upper limit on the number of possible rewards can be a significant negative.

The Priority Club promotion caps its offer at four free nights per member. Members of Starwood's program can earn an unlimited number of free nights. So Starwood's offer is potentially more generous.

Promotion duration: Starwood's offer runs from May 1 through July 31, and Priority Club's is in effect between May 4 and July 3. Longer is always better (more time to earn bonuses), so Starwood wins this one.

Network size: When it comes to hotel chains, size — the number of individual hotel properties — translates into increased flexibility and convenience, both in terms of earning and redeeming the free nights.

Starwood's program has around 875 properties, Priority Club about 4,000.

By almost a five-to-one margin, Priority Club trumps Starwood.

And the winner is ...

For the average traveler, InterContinental ekes out a win over Starwood with easier earning and more convenient redemption. If the promotion were in place longer, it would be an even clearer winner.

Of course, travelers already vested in Starwood's program may wish to take advantage of that chain's weaker offer anyway.

Maintaining one's progress toward earning an award, or attaining elite status, sometimes outweighs the payoff of a short-term promotion.

This is just a single round, between two of the many larger hotel chains. Winners and losers will change, with one hotel group nailing it this time only to be one-upped by a competitor during the next period of promotional activity.

What remains constant is the requirement that consumers look beyond the marketing headline to determine the real value of a travel offer.