My memory is really fuzzy, but I recall back when the new IM apps were all coming out and competing for the small share of people wanting to test them, either the Wire app or using the Wire service had a hard cost ($5 USD?) (no free-to-test tier, you had to pay to use). I believe history has shown a vast majority of folks will choose free (even with ads, sadly) over a hard cost for IM. Signal talked a better game and offered everything for free.