From the article:
"Frontier CEO Barry Biffle said the Las Vegas flight is the start of what the airline hopes will be a major expansion in Colorado Springs that could become a quarter to half the size of its Denver hub with flights to 15-20 destinations within three to five years. if the initial flight is successful in attracting passengers. He said last week Frontier is pleased with initial bookings. He mentioned at a Jan. 12 news conference that Phoenix was high on Frontier's list of potential destinations - a Phoenix-Springs route was shown by mistake for a short time on Frontier's route map - along with cities in California and "some in the Central time zone."

Biffle pointed to the ability of Western Pacific Airlines to draw large numbers of passengers to the Springs with low fares 20 years ago as evidence that Frontier can grow in southern Colorado. Amid growing losses, WestPac eventually left Colorado Springs for Denver and later collapsed in bankruptcy.

Boyd sees plenty of opportunity for Frontier in Colorado Springs. He sees Florida as an attractive destination because it will pay far less to the Springs airport in rent and fees - about $6 per departing passenger - than it would at DIA. There, such costs are about double, plus Boyd believes DIA is headed toward higher construction costs for the new hotel connected to the passenger terminal that opened in November. Depending on Frontier's growth in the Springs, Colorado Springs Airport officials estimate that the cost airlines pay per departing passenger could drop by as much as half to about $3.

"You will see a larger percentage of people from the I-25 corridor using Colorado Springs, particularly those from south of Castle Rock," Boyd said. "While a large number will still go to DIA, a greater share will go to the Springs than they have in the past. You will see more people using that airport.""

1/4 to 1/2 the size of Denver... Wow! Florida (probably MCO) and PHX out of COS would makes sense; even though I hate to agree with Mike Boyd.