Ting needs a (preferably GSM) partner that offers better coverage options than their current partners.
Due to coverage holes with both current partners, I have had to move my mobile devices to a different carrier, leaving only my home phone on Ting. Even then, I see its coverage appears to be marginal.
Ting has some great ideas to shakeup the mobile phone industry and has caused some major changes, but the re hampered by their choice of network partners. This became quite obvious to us in the past year as we started looking for a new house. There were several areas with no Sprint, T-Mobile or Ting GSM coverage, but Verizon worked and maps said there was goo AT&T coverage too.
People expect cellular phones to just work wherever they normally travel domestically.