Because lead generation is the first step in the sales process, both quality and quantity are important factors. Quality leads are leads that a salesperson has a good chance of closing, which means they must at least have the potential to become customers. Every lead list will have a number of junk leads – people who are not qualified to buy the product for some reason – but the smaller the percentage of bad leads, the less time salespeople will waste while processing that list. Quantity is also important because even a salesperson with a list of 100% good leads won't be able to close every one of them. A salesperson with 100 good leads might be able to make 10 appointments, out of which 4 will close the sale. Therefore, if a salesperson has a quota of 40 sales per month, she will need 1000 good leads per month just to make the minimum required number of sales.
Unsurprisingly, the more revenue a company has, the more leads they generate. The differences are most drastic at the highest and lowest end of the spectrum: 82% of companies with $250,000 or less in annual revenue report generating less than 100 leads per month, whereas only 8% of companies generating $1 billion in annual revenue report less than 100 leads per month.