The likely answer is to do with audience biases. A survey conducted by an email marketing provider is almost certainly going to have different results to one conducted by PPC management tool, as their audiences have different skillsets and biases, skewing the results of their sample. As such, we should take the specific ranking of different strategies in these studies with a pinch of salt.
By being selective with your direct mail efforts, you can invest more in the physical item you’re sending out. Plus, you can offer better discounts, coupons, or other enticements to get new leads to take the next step. Think of direct mail as your first foray into getting someone to go to your website or call you, rather than your final step in getting new clients.
In marketing, lead generation is the initiation of consumer interest or enquiry into products or services of a business. Leads can be created for purposes such as list building, e-newsletter list acquisition or for sales leads. The methods for generating leads typically fall under the umbrella of advertising, but may also include non-paid sources such as organic search engine results or referrals from existing customers.