This challenges the author’s assumption that newspaper subscribers will consider personalized news a replacement for newspapers. The services described will not allow people to casually browse for stories on topics they don’t subscribe to.

This doesn’t say those prices will be too expensive for newspaper subscribers. It’s possible even the most expensive personalized news service will be more affordable than a current newspaper subscription.

This implies at least some people are satisfied consuming only television news. It doesn’t challenge the prediction that newspaper sales will drop.

This strengthens the argument because it means the personalized news service will not be too expensive for the typical newspaper subscriber to afford. It eliminates one possible reason to doubt the author’s prediction.

This strengthens the argument because it means the personalized news service will not carry upfront costs for most customers. It eliminates one possible reason to doubt the author’s prediction.