Each lead generation technique usually has a tradeoff between quality and quantity. For example, a form on the company website that visitors can fill in to request a call back will generate high-quality leads – these visitors are very likely to buy since they're interested enough to want to hear more – but probably won't generate a lot of leads. On the other hand, a lead list that's based on a newsletter subscription list from another company may generate a lot of leads, but they won't be nearly as interested or qualified.
Leads may come from various sources or activities, for example, digitally via the Internet, through personal referrals, through telephone calls either by the company or telemarketers, through advertisements, and events. A 2015 study found that 89% of respondents cited email as the most-used channel for generating leads, followed by content marketing, search engine, and finally events. A study from 2014 found that direct traffic, search engines, and web referrals were the three most popular online channels for lead generation, accounting for 93% of leads.