I will talk more about lead management in later sections but as it relates to brand, how you manage your leads definitely relates to customer experience and your brand.  As you bring a visitor through the classic awareness --> interest --> desire --> action cycle, you want to make this a positive brand experience.

Visitors that convert are a great opportunity for repeat business and referrals.  There are many opportunities to reinforce your positive brand in the exchange.  Offer brand value and confirm that your visitor made the right decision in choosing your product or service.  Coach them about how you might serve them again or they might work with you in the future. You need to do this both with on screen confirmations where you are certain they can see it and with confirmation emails and shipping notices to reaffirm that you are here for them.  Finally, watch out for spam filters here.  It is typical for spam filters, firewalls, and internet outages to derail a connection.  Verify that your users get your communications where possible and follow up with humans if you run into problems.

Agree with your customer and your sales channel about what a good frequency of contact would be for their needs.  Reinforce your brand with every repeat touch.  Permission for access once granted is the open door to repeat business.  Your customer has already shown that they are willing to trial your brand, now you want to confirm that you are engaged, committed to their success, and can be trusted.  Protect this trust and the customer will reward you.