One of the regular criticisms of Ayn Rand is that she had a transactional view of relationships, which seems more like a lazy way to use economic models to interpret relationships than an inherently productive view of them; it isolates relationships in terms of some universal currency and then assigns values. She didn't; a transactional view of relationships would isolate relationships down to a currency that is paid back and forth. Her "currency" was "values," and was functionally rooted in the idea that relationships are an end product of two people's moral systems, independent of what they do for each other. You can't make a relationship better by sending somebody flowers; you send them flowers because you want to give them flowers, not to try to heal a cracked relationship.
Try applying the transactional relationship model to a train and you quickly see the problem: You can't compensate for a cheap engine that can't pull a train by installing very expensive chairs for the passengers. There's no exchange rate in the world that can convert comfort into horsepower.
Likewise with relationships, which are abstract enough that it can almost seem like it could work, until you actually get into the specifics. People who focus on some central value repository - frequently called love, although depending on circumstances it can get called many different things - miss the point. A forgotten anniversary doesn't subtract ten love points, and flowers and a handwritten apology letter don't add six back.
The transactional model Ayn Rand was criticized for seems more prevalent in the general culture than in Objectivists; people don't choose money as their store of value, but they do try to invent a store of value, and it doesn't really work. There isn't some pot called love that you can pour a little water into every day, and simply being kind to somebody, or sending them flowers every day, isn't going to make them love you. At best these are signaling behaviors, indicating some quality about yourself, which you are demonstrating/proving to the other person; it is that quality that they will love, or not love as the case may be, not the act of giving flowers itself.
Ayn Rand described relationships in transactional terms - as being value for value - but the values she refers to are non-transactional; you cannot give somebody your virtues, nor do you trade virtues; you value your mate for their virtues, and they value you for yours, but in no sense does this make a relationship a transactional experience.