[mike-cardwell]

That's only a problem as long as ad funded versions exist. Get rid of the ad funded versions and it's no longer a problem, as the non-ad-funded versions will no longer have to compete with them.

Plus, many useful services will still have free versions, and then provided paid upgrades.

Plus, many useful services will stop being centralised, distributed, free, peer to peer versions will be created that cost nothing to host, and they will be popular, because there are no ad-funded versions to compete.