What is shared vs dedicated infrastructure?

ESP pricing commonly follows one of several primary models: subscriber-based pricing charges by the number of contacts in your database regardless of sending volume; send-based pricing charges by email volume regardless of list size; and tiered plans combine features and limits at fixed monthly rates. Some ESPs use hybrid models that factor in both subscribers and sends, with overages charged separately.

Subscriber-based pricing favors senders who email frequently since you pay the same whether you send once monthly or daily. Send-based pricing favors those with large databases but moderate frequency. Understanding your sending patterns helps you choose the most economical model. Also watch for how ESPs count subscribers: some charge for all contacts including unsubscribed, while others only count active subscribers.

Beyond base pricing, consider additional costs for premium features, dedicated IPs, advanced automation, increased API access, premium support, or professional services. Some ESPs include generous features at lower tiers while others upsell aggressively. Contract terms also vary from monthly flexibility to annual commitments with discounts. Model your costs at current scale and projected growth to avoid surprises. The cheapest ESP isn't always the best value; factor in deliverability, features, and support when comparing total cost of ownership.