While it looks like American plans to follow Delta by introducing Basic Economy Fares (lowest fares that do not come with the ordinary benefits of a ticket on a full service carrier, such as advance seat assignments or the ability to upgrade or even make changes with payment of a fee), there’s some indication that United may follow American’s existing model of selling bundles of benefits with their tickets.
And they want to use miles for inflight purchases and for ancillary services during the booking process.