The presence of Spirit Airlines continues to grow at Minneapolis St. Paul International Airport, but its popularity with travelers remains under review.

After adding service to Baltimore and Houston, the Florida-based low-fare carrier announced Thursday that it will offer seasonal nonstop service between the Twin Cities and Detroit effective May 22 and operating daily until Nov. 1.

The new service to Detroit brings to 13 the number of nonstop destinations that passengers can reach from the Twin Cities as Spirit continues to build its presence in northern-tier cities including Chicago.

"Now even more customers going to or from the Windy City and the Twin Cities will be able to save with our insanely low fares," said Mark Kopczak, Spirit's vice president of network planning, in a statement.

However, airline industry experts expressed caution about Spirit's market acceptance, given the additional fees for everything from carry-on luggage to online booking.

"Spirit is attractive to people strictly concerned about the lowest fares, but when people are nickel-and-dimed to death, that's a turnoff to a lot of consumers," said Steve Loucks, chief communications officer for Plymouth-based Travel Leaders Group.

A round-trip fare from the Twin Cities to Detroit in May is listed at $178, according to The current average fare on a Delta flight is $259 each way, according to the Metropolitan Airports Commission.

"We look for routes with high prices which we feel can be stimulated through lower fares, thereby generating new customers," said Maggie Espin-Christina, Spirit's corporate communications manager, in an e-mail.

While Spirit will have one flight a day between the Twin Cities and Detroit, Delta, which maintains a hub in Detroit, will have nine daily flights.

The likely result is competitive pricing only on the Delta flight closest in departure time to the Spirit flight, said Lori Raduenz, president of the Minneapolis division of the travel management firm Acendas.

But, said Raduenz, "With one [Spirit] flight a day, if something goes wrong you're really in trouble. Delta has a lot more flights." She also said Spirit travelers "will have to pay so many add-on fees just to get close to the basic service level of Delta."

Nonetheless, Spirit has tapped an audience of disgruntled travelers who will pay fees and/or forgo services in order to obtain low fares.

According to Spirit, systemwide passenger traffic was up 24 percent in January 2014, compared with a year ago, while the percentage of occupied seats last month rose 1.6 percent to 85.5 percent of capacity.

Moreover, net income for the third quarter of 2013, the most recent earnings report, was up 130.3 percent to $57.9 million while operating revenue was up 33.4 percent to $456.6 million.

"We target the price-sensitive and leisure customer," said Espin-Christina.

Spirit started service in the Twin Cities in 2012 and offers nonstop service to Las Vegas, Los Angeles, Denver, Dallas-Fort Worth, Baltimore, Detroit and Houston as well as vacation destinations in Florida.

Staff writer Paul Walsh contributed to this report.