Subscription services for extra legroom, increased baggage allowance, and even ‘all-you-can-fly’ programs are making their debuts in the airline industry, in what could become the next trend in flying.

Earlier this week United Airlines launched a new service that would allow subscribers to book seats which offer extra legroom at the front of economy cabins for a flat fee of $500 a year.

Their new baggage subscription service also allows flyers to check up to two bags for free on all United flights for a rate starting at $349 a year. Currently, travelers on domestic flights pay $25 for the first bag and $35 for the second bag. On international routes passengers are allowed to check one bag for free and must pay $100 for their second suitcase.

Meanwhile, Santa Monica-based airline Surf Air has launched an “all-you-can-fly” subscription service that would allow members unlimited flights within the US for a flat rate that starts at $790 a month.

The private jet service is operated on a Pilatus PC-12 with BMW-designed leather interior seats which can accommodate eight passengers.

And in addition to personal concierge services, a monthly subscription entitles members to bring additional guests onboard for free, provided reservations are made two weeks in advance.

To begin, routes serviced will include the San Francisco Bay Area, Santa Barbara, and the Los Angeles Metro Area before expanding to to the rest of California and nationwide.