The issue of BigCo's closing useful small services just to harvest the developers post acquisition is certainly a valid one that's worthy of debate.
However, the premise that this only happens because the startup in question was "free" doesn't hold weight. Call me a cynic but the recommendation to use "paid-for" services only to avoid this outcome just seems a little too self-serving to paid-for-only service PinBoard (as excellent as it is).
I don't have an exhaustive list of startup acquisitions that were then shut down, but here's a few just from a Google acquisition list I found:
* PostRank was a paid-for blog data service Google acquired, shut down
* Jambool was a virtual gold payment processing system Google acquired, shut down
* Gizmo5 was a VOIP service Google acquired and shut down.
In some cases even if a company is taking money that alone still doesn't make it viable. In other cases, like PostRank and Jambool where the $$$ being paid by customers was probably significant, acquirers like Google have other circumstances where they'll shut a profitable businesses for a 'higher goal' in a bigger project.
I believe the point is less about revenue being a guarantee that it won't happen and more about the fact that a lack of profit makes it increasingly likely that the product will eventually be shuttered because free isn't a sustainable model.
That's the claim that I'd like to see some data to believe: are, in fact, paid cloud services more long-lasting than free or freemium services? My guess would be no, that a large number of them also go bankrupt, are acquired and shut down, pivot to other lines of work, or otherwise fail to stick around.
I'm with you on your guess. There are hundreds of reasons why a paid service may stop to exist. Still I would argue that running a paid service gives you more options compared to free/freemium: if you balance right you should not go bankrupt, it's cheaper to run (less users -> cheaper hosting and less support), better position to fend off acquisition or during acquisition-negotiations, easier to bootstrap.
But that also doesn't really ring true either because a "lack of profit" doesn't necessarily mean that an acquiring party will shut said service down either.
I doubt Friendfeed makes Facebook any money, and was clearly a talent acquisition (Bret is their CTO now) but they still keep it running.
You're right that anyone using any tool/service with an unsustainable model needs to be cautious. But there's a lot more to it then is being proposed by the OP.
They keep the lights on, but Friendfeed might be as well dead. The impression of activity is maintained by posts imported automatically from connected accounts, and the list of supported sites haven't been updated in years. For example, neither Rdio, Spotify, nor Grooveshark are available in the music section, same with Instagram and picplz in the photos section.
However, the premise that this only happens because the startup in question was "free" doesn't hold weight. Call me a cynic but the recommendation to use "paid-for" services only to avoid this outcome just seems a little too self-serving to paid-for-only service PinBoard (as excellent as it is).
I don't have an exhaustive list of startup acquisitions that were then shut down, but here's a few just from a Google acquisition list I found:
* PostRank was a paid-for blog data service Google acquired, shut down
* Jambool was a virtual gold payment processing system Google acquired, shut down
* Gizmo5 was a VOIP service Google acquired and shut down.
In some cases even if a company is taking money that alone still doesn't make it viable. In other cases, like PostRank and Jambool where the $$$ being paid by customers was probably significant, acquirers like Google have other circumstances where they'll shut a profitable businesses for a 'higher goal' in a bigger project.