Make third party product dependencies transparent. Ex: if your product works only with the Google ecosystem make it clear. Or if you need incorporation in a specific country to get the related payment gateway (like ChargeBee does), then make it transparent.

Qualifying the prospect:

• Identifying the one activity that you want users to experience to get started with your product is essential. It could be adding another user, or creating a specific setup or configuration in your product.
• Keeping track of customer activity via detailed logs, understanding the source of signup & journey in the website followed by application is essential to understand the quality of prospect.
• In some cases asking for phone number & reaching out quickly via phone through "Inside Sales" also helps short­circuit the process. However, this experience varies by culture, nature of your product & persona of your customers.