Through August 31, new members who enroll in Frontier Early Returns receive 1000 miles.
A year and a half ago they ran a 1500 point signup bonus, and I recommended signing up just to convert the miles to a $6 Starbucks gift card.
Frontier participates in Points.com, and you can convert 1000 miles to your choice of (among other options):
- 184 US Airways miles
- 297 Priority Club points
- 138 Delta miles
- 297 AsiaMiles
- 148 Aeroplan miles
- 153 Contiental miles
- 153 American miles
You can use the opportunity to extend expiration on an American or US Airways account, for instance.