It appears T-Mobile once again took home the lion’s share of net additions in the fourth quarter, and consumer perception of value in carrier plans could be a factor in the Un-carrier’s success.

According to a new report from YouGov BrandIndex, following the Christmas holiday, consumer value perception for Verizon dropped to its lowest point in at least the last six years. And AT&T isn’t fairing much better. The report noted Big Blue’s value perception has fallen steadily through the month of December, dragging AT&T to the back of the pack.

YouGov’s Ted Marzilli noted Verizon’s drop could be related to bad press surrounding its decision to drop or downgrade to a lower plan customers who use more than 200 GB of data in a month.

Marzilli also speculated AT&T’s declines could be related to its decision to raise the price of DirecTV anywhere in early December. It’s also possible, though, that AT&T’s problems could be related more to the hiccups with its DirecTV Now mobile video product, which have left consumers frustrated. More on that can be found here.

Whatever the causes of Verizon and AT&T’s misfortunes, Marzilli observed the drop has left an opening for T-Mobile – and, to a lesser extent, Sprint – which has been leading far and above since Christmas.

YouGov BrandIndex indicated its data comes from a survey of 35,000 adults ages 18 and up who were interviewed over the past 13 months. Approximately 4,800 adults are interviewed each weekday in the U.S. and asked of their service with the carriers “Does it give good value for what you pay?”