The English language is vast and has numerous synonyms for a single word or phrase. Similarly, 'to the advantage/profit of' has many synonyms that can be used depending on the context. Some of these synonyms include beneficial, useful, favorable, profitable, advantageous, fruitful, gainful, helpful, rewarding, and advantageous. Each of these words has its own shade of meaning and can be used in different situations. For example, 'profitable' is more suited for commercial purposes while 'helpful' is more suited for personal use. Choosing the right synonym can help to add variety, precision, and eloquence to one's language.