Buyer data is the new business currency, but data gathering is a gambler’s game. The more data a lead generation team has, the more likely they are to find actionable leads. Then again, some lead generation companies source and resell leads, buying them from other providers and selling them to you at markup. This not only means you pay more per lead to cover the middleman costs, but you also run a higher risk of getting outdated or unethically sourced leads.
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. This tradeoff is another reason why companies are wise to use many lead generation methods.