Is it permissible to deal with an affiliate marketing company that pays $55 for every new customer who makes a purchase for $14, knowing that it might later send impermissible advertisements to customers, and are the profits resulting from this permissible (halal) or impermissible (haram)?

It is permissible to work as a commercial intermediary between websites and customers under two conditions: that the commission is known (and it is permissible for it to be a percentage of the selling price or profit), and that the purchased commodity is permissible. It does not matter if the commission is more than the price of the commodity, or if the website sends prohibited advertisements after attracting the customer, as long as you have guided them to a permissible commodity.