From today through to Monday, January 25th, Sprint has a 4-Day Dash promo that might be worth checking out. You can save up to $200 when you trade-in a working smartphone toward a new LG G4 and Sprint's service. This offer is in addition to (stacks with) all of Sprint's other current offers. Here's a quote with more of the details,
  • Sprint offers the opportunity to switch and save 50% off most AT&T, T-Mobile and Verizon rate plans[1].
  • Sprint delivers the fastest LTE Plus download speeds according to Nielsen Mobile Performance data[2]—faster than Verizon, AT&T and T-Mobile.
  • Sprint covers your switching fees up to $650 per line, via American Express reward card after online registration[3].
  • Switching is easy! You can visit a Sprint store, go online or call 1-800-SPRINT1 to make the switch from your current carrier to Sprint. And, you can keep your same phone number.
  • With Direct2You, you can have a Sprint expert deliver a new phone to you virtually whenever and wherever you want – for free.
  • This weekend, you can get a minimum $200 trade-in on any smartphone when you purchase an LG G4. Check back at for future limited-time-only offers.

For more info, here's Sprint's promo link: Now’s the Time to Switch to Sprint and Save $200 When You Purchase LG G4 and trade in any smartphone | Sprint Newsroom