For me one part of "growing up" in sw engineering has been that I have started to want to pay reasonable amounts for things I use actively.
I see it as an insurance for us users: as long as a significant amount of users are paying keeping the service as-is is a valid alternative for the owners.
When it becomes free I fear that someone suddenly starts looking at it as a cost center, I mean: all the benefits you mention seems to be possible without operating an end-user service.
Disclaimer: not a paying Instapaper customer, but I am a paying lastpass customer and a paying google docs customer etc etc.
I don't have a statistical survey, but I have anecdotal evidence of paid services going away, increasing in price dramatically, or remaining the same. Same with free services.
I can't honestly say that the paid-for services I use are more likely to remain available than my non-paid services.
The key factor appears to be a viable business model, but that's impossible to evaluate from the outside (and sometimes from the inside).
I see it as an insurance for us users: as long as a significant amount of users are paying keeping the service as-is is a valid alternative for the owners.
When it becomes free I fear that someone suddenly starts looking at it as a cost center, I mean: all the benefits you mention seems to be possible without operating an end-user service.
Disclaimer: not a paying Instapaper customer, but I am a paying lastpass customer and a paying google docs customer etc etc.