A good analogy for this is crop rotation. Farmers know that every time they plant the same crop on the same land, the soil quality and crop yield diminishes. They rotate their crops to return appropriate nutrients to the land and balance the soil quality.
Marketers need to do their own crop rotation by changing the campaign strategy and messaging to boost yields. As marketers learn more about contacts during the first harvest—such as what technology they use, which issues they face or who makes the buying decision—messages should be refined and contacts should be segmented to make the remarketing effort even more relevant. A good way to do this is to align case studies that are highly relevant to the contact's industry or existing technology stack.
Letting the Soil Rest
During crop rotation, it is common practice to add a fallow period to the rotation. During this time, nothing is planted and the soil is allowed to rest. This is important for second harvest lead generation efforts, too.
An initial lead generation campaign should be followed by an appropriate rest period before going back to the dataset with another campaign. The length of the rest period depends on the industry and the product or service being marketed. Generally, marketers should allow a dataset to rest for at least half the average sales cycle for an enterprise sale, and a full sales cycle for a non-enterprise/SMB sale.
This amount of time will give leads time to ripen so the second harvest will be bountiful.