One of the main reasons to have a website is to get people "into your world". By that, I mean they're actively engaged with your company at some level: they're on your email list, connected with you on social media, or are in conversations with your sales team.
The only way to get someone into your world is to get them to willingly give you their contact information. It's a little counter-intuitive: we usually think of prospects running away from salespeople as fast as possible, and yet here I am saying that they need to self-select into the sales process.
How in the world does that happen?