To ensure that your leads are nurtured effectively one needs to ensure that they are informed of newer additions to your product, they need to be made involved, so keep them hooked by asking them to view a demo, take part in a webinar, read a blog etc. Educating your lead about the product, its effectiveness through a well-thought of email campaign also might work wonders. The onus lies on nurturing your relationship with your prospect, which means you need to cultivate your relationship and care for it continuously.