Valuation tips - "boring" business, but with e-commerce distribution

When evaluating a business such as a manufacturing business that might normally sell for 2x-3x EBITDA, what adjustments would you make for an ecommerce component? For instance, if 50%, 75%, or even 100% of product is sold through an ecommerce system - no sales force required and a fair percentage or repeat customers.

I know that some ecommerce companies are valued at a higher multiple even if they are not actually fulfilling their own orders; I'm curious how valuation is impacted when the company controls both the actual manufacture and also the distribution through ecommerce.