When the internet first began general use, spam emails were a popular way to advertise goods and services. Over time, email service companies learned how to spot and stop spam emails. This has long been a service provided by email servers. While many of these emails are simply a way to market products and companies, some of them have been loaded with virus programs. Companies now work to collect email addresses as leads and get permission before sending sales emails. While this is more costly for the company, their message will get through to consumers truly interested in purchasing their products.