The minimum offer is 2 seeds, but the site automatically deducts one seed during each follow. That's why offers always appear one seed lower than you set them. If you set it to 2, it will appear as 1. If you set it to 6, it will appear as 5. Deducting one seed during each follow is a very important part of the seed mechanism. It allows us to reintroduce those seeds into the system in other ways, such as giving them to new users or to users who refer other users or blog about the site.
It creates a better "flow" of seeds on the site that encourages a lot of following. If we didn't do this then the seeds in the system would inflate, and the incentive to follow others would diminish over time. We would also not be able to offer incentives for referrals and other community growing activities. All of this we have found out through extensive testing and analysis.