A ponzi scheme is great for all the outside investors who get in early (and leave early).
This by contrast is entirely worthless for notifying outside help in case of a backcountry emergency.
All it does is allow your phone to be used for two-way MURS-band texting ... and only with other goTenna users ... and only within a short range:
"Under normal circumstances, expect to be within a mile or two of someone instead."
"[...] around 1 mile in skyscraper-filled urban areas, but up to 9 miles in most outdoor situations like hiking and camping. If you're climbing or, say, out skiing, it shoots from 9 miles to as high as 50 miles once you start ascending to higher elevations."
"GoTenna says its devices will transmit up to three miles in the woods or eight miles over open water."
"Perdomo says in a city the low-frequency radio waves reach about a mile, but in an open field it can reach about 50 miles."
"For example, at the top of a mountain, a GoTenna could find devices up to 50 miles away. But when in the center of a forest, it might only be able to reach three to four miles away."