Learn from the experts, I always say. You know who the experts are for this purpose? The writers of Romance.
Something like 50% of all fiction sold is in the Romance genre. The most successful writers in this genre (and some are very successful) are specialists in volume and audience targeting.
Generally speaking, Romance readers are high-volume consumers of their favorite authors. Several books/week is not unusual. No one author can produce enough to satisfy them (though many are incredibly prolific), but they can be confident of selling each new work to their standard audience, which is a great motivator to pin down exactly what their audience wants.
The good news is that there are scores of romantic setups that work for one person or another, and for minute romantic specialties. The bad news is — disappoint one of your readers by not satisfying her (and it's usually “her”) expectations, and she may be gone forever.