I don’t find the advertising intrusive at all (I’m used to ‘mentally’ filtering it out), except on mobile browsers where the ads block the ‘Reply’ button. Ideally, there would be no advertising, but as @Tis_Bearself and others wrote, Catholic Answers doubtless has a modicum of expenses.
I don’t know why the use of advertising revenue is being characterised as ‘serving Mammon’. Moreover, Catholic Answers is a lay apostolate, and the Holy See’s understanding of such ministries is outlined in
Apostolicam Actuositatem . The decree places no expectation on the laity that their evangelising and sanctifying activity must be conducted
gratis (that is, without expectation of monetary compensation) nor that it must be shorn from from the world. In fact, the decree states that:
[The laity’s] apostolic formation is specially characterized by the distinctively secular and particular quality of the lay state and by its own form of the spiritual life.
Each person has to find his own way to
exist in the world and
serve - and
live in - the Lord during this one lifetime we have here, temporary that it is. I like St. Paul’s way here:
Act 18:1 After this he left Athens and went to Corinth.
Act 18:2 And he found a Jew named Aquila, a native of Pontus, lately come from Italy with his wife Priscilla, because Claudius had commanded all the Jews to leave Rome. And he went to see them;
Act 18:3 and because he was of the same trade he stayed with them, and they worked, for by trade they were tentmakers.
Act 18:4 And he argued in the synagogue every sabbath, and persuaded Jews and Greeks.
That is, he worked at his trade to earn money, and served God on the sabbath. I’m sure his tent-making was good and honorable in the eyes of all, that his character was notable and blameless, above reproach - as expected of a Christian. But when he was preaching and teaching the things of God, he did not take “commercial breaks” to sell people on his tent making skills. He did not mix God and Mammon. He did not demean holy things of God, by mixing them in secular matters and concerns.