Can financial incentives be used to make converts?

Did it reflect poorly on St. Francis De Sales that he offered a bribe to convert Beza?

The short answer is no.

Buying someone's conversion or forcing someone to convert to the Catholic faith would not be a valid conversion.

The Catholic view of the interviews between St. Francis de Sales and Theodore de Bèze will be viewed in the light of the Catholic faith and Calvinists will view them in the Calvinist (Protestant) light. That much is normal.

We do not know the date of the third interview, but according to Charles-Auguste de Sales, it had taken place. Francis offered Theodore de Bèze, on the part of the pope, an annual pension of 4,000 écus of gold if he would leave Geneva. He refused. The tenor of this third interview profoundly shocked the Protestants. They interpreted it as a corrupt maneuver by the Roman Church to buy the conversion of Theodore de Bèze. In reality, the Catholic Church thought that in proposing to him that he leave Geneva, the Reformation would be profoundly weakened. The money was destined not to make him decide to convert, but to make him leave the Reformed Rome (Geneva). But the evil was done. The visits of Francis de Sales had already been found suspect. They stopped there. Youthful and without doubt a bit utopian, Francis de Sales undoubtedly did not consider thoroughly that Theodore de Bèze was too rooted in his reformed faith and in his city of Geneva to cede to his gentle but firm evangelical pressure to convert himself. - Mission according to St. Francis de Sales, based on his mission to the Chablais

There may be some imprudence on behalf Pope Clement VIII of to ask St. Francis de Sales to offer a pension to Theodore de Bèze, if he agreed to leave Geneva which was being called the Reformed Rome. The pope simply wanted his adversary to leave and thus strengthen the Catholic position in Geneva, which was being known as a sort of new Protestant Rome. The pope was certainly afraid of the possible outcome if Theodore de Bèze did not leave Geneva. And for both sides the stakes were high.

Geneva, Switzerland’s second-largest city, is located in the Rhône Valley near the French border. Situated next to the Swiss Alps, Geneva enjoys an idyllic setting on one of the biggest alpine lakes and within view of the snow-capped Mont Blanc. Not only is Geneva a stunning city, it is rich in Reformation history. Geneva has several sites of religious interest, most notably those associated with John Calvin, the Protestant Reformer second in importance only to Martin Luther.

Calvin led the Reformation in Geneva for decades, making his home in the city and preaching at St. Peter’s Cathedral. Calvin died here in 1564, but his legacy lives on. Geneva became famous as a model of an ideal Protestant city, and reformers from all over Europe came to Geneva to learn from Calvin and his colleagues. Geneva’s role as the “Protestant Rome” is commemorated in its large Reformation Monument.

Theodore de Beza was a close friend of, and collaborator with, Calvin. When Calvin died, in 1564, he became his successor as the spiritual leader of the Republic of Geneva. Although Beza was not quite ten years junior to Calvin, he survived him by over forty years.

He was a scholar and a very influential Protestant who had travelled widely in France and Germany as well as Switzerland. By the late 1590s he had relinquished most of his public duties and was in his late seventies (he was born at Midsummer in 1519).

St. Francis de Sales was, in April 1597, not quite thirty. He had already had some success in converting Protestants to Catholicism and had received permission from the Pope to read Calvin's Institutes and other works.

The Protestant cause in Europe had been weakened by the conversion to Catholicism of Henry IV of France, in 1593. He was said to have remarked "Paris is worth a mass."

St. Francis de Sales and his friend Esprit de Beaume conceived a plan to convert Beza to Catholicism. Beaume was to obtain from the Pope assurances that Beza would be welcomed if he converted to Catholicism. Sales was to use his skill and zeal to persuade Beza that his Protestantism was in error.

The renunciation of Protestantism by such an influential figure as Beza might be expected to cause a collapse in confidence in Protestantism, and not only in France. Sales and Beaume did not seek to convert Beza solely out of a concern for Beza himself, but for the weakening of the Protestant cause generally, and so indirectly for the conversion of many.

De Sales met with Beza in Beza's home, which had been Calvin's home, in Easter Week 1597, and again later that month. Both had been born into minor nobility. Both were keen and zealous exponents of their respective beliefs. Beza was 77 and Sales 29. Neither man converted the other. Sales was initially hopeful in that Beza conceded some of his points, but that did not mean Beza accepted Sales conclusions. Neither man converted the other.

In July, realising that Beza was not about to change his beliefs, De Sales offered him, on behalf of the Pope, a lump sum and a pension for life, if he would at least abandon Geneva. Beza refused to hear any more. Beza had been in receipt of a pension from Henry IV which ceased on the latter's conversion, and still had his pastor's salary.

De Sales would have liked to convert Beza, but failing that bribing him to abandon Geneva, or to renounce Protestantism insincerely (the terms which might have been agreed cannot be known since Beza drew the discussion to a close) would also weaken Protestantism and so was a good thing, from a Catholic perspective.

Having failed to convert Beza, or to induce him to leave his post, the next best thing was to convince people that he had done so, or was about to do so. Rumours were circulated that Beza and the Republic of Geneva were returning to Rome. The people of Sienna, in Italy, were convinced Beza would pass through Sienna on his way to Rome and gathered to welcome him at the time he was due.

Rumours then began that Beza had died on the way to Rome, or had converted on his deathbed in Geneva. Beza himself assured people he was alive and Protestant.

De Sales did not believe that he could buy Beza's conversion, but did hope to buy his influence.

Whether this reflects poorly on him is ultimately a matter of opinion, and will depend on how important one feels it was to weaken Protestantism, and in so doing bring many to the Catholic Faith.

This article describes the matter from Catholic sources. See also this.