SEA, SEO
Lead
A lead is a contact that was acquired through the website or advertising banner. A lead can be an email address, a telephone number or similar. It is only important that the lead enables further contact, which has the goal of turning the lead into a customer or a deal.
Not every lead is of equal value. A common approach is to classify them based on how concrete the interest is: someone who downloads an information sheet is at an earlier stage than someone who requests a quote.
The legal framework is important. Anyone who collects contact data via a form and wants to use it later for advertising needs consent and an understandable privacy policy.
More on measurement and campaigns under Online Marketing.
Other topics
Interested in other topics? Here we have a few more suitable explanations.