Ahh but how relevant is ad-support when Gmail is accessed via a MUA ?

Absolutely, in the context of Open Source/Free Software as a development model for software it isn’t important (or even relevant) that people buy/purchase software. However, what is somewhat of note is that the model lends itself to a society where infrastructure can function without ‘paying for software’ and ‘subscribing to services/support’.

The nub of that statement is that the world of lock-in software or, a stage where binary bits are priced isn’t quite true. There is an alternative that sometimes most people who begin to use-consume FOSS tend to miss.

Some of us use gmail but via a desktop client that shows none of the ads. Maybe the value of gmail is more in brand propagation and custom deployments for enterprises rather than ads.

There is nothing inherently good or bad about “not buying software in the past ten years.”

If you put value in it, there is nothing wrong with that value being a monetary one. Open Source only talks about the freedom to use it; not the freedom to place whatever value (even monetary) on it. If a person wants to purchase software that he/she finds useful (and we’re talking of ‘purchasing’ outside the situation of being locked into a closed-source product) then there’s nothing wrong with that.

And the corollary is, that if a user genuinely admires a piece of closed-source software and wants to use it — even pay money for it — there’s nothing wrong with _that_. You can’t take away the value he/she puts on that software himself, or say that he has misplaced his value — value (and software value) is obviously subjective.

The fact that you haven’t bought anything means you’re quite satisfied _not_ buying anything. But it doesn’t mean other people can’t find satisfaction in investing monetary value in a piece of software. This doesn’t contradict the FOSS development model at all.