In fact most spammers need only one positive response in order to make a profit - and they often rely on this fact. This can mean hitting many millions of addresses at a time, and it doesn't matter how many sellers there are - because chances are if the seller hits millions of addresses, one of them will respond positively, even if most of the addresses received thousands of advertisements that day. There is no real equilibrium effect as there is in the case of direct mail. The Recipient Money, Direct Mail Costs the Recipient Nothing Direct mail costs the recipient nothing - people don't pay for the amount of mail received. All costs are imposed on the sender.
Direct email imposes significant costs on the recipient.
Firstly, in Australia we pay for the amount of data we receive, and email is data and hence we pay for it. Even if you don't get charged for data, your ISP does, and you can be sure they have factored this into their fees. Additionally, ISPs require additional resources to process spam - larger servers, more disk space, and bigger and more expensive connections to the rest of the Internet. Users end up spending more time on the Internet because it takes time to download spam, and this additional time is reflected in increased time charges. In fact, due to these differences between the cost models, spam is actually more expensive to the recipient than direct mail .