Don't forget about B2M (Marketers).
Companies like Wufoo, Mailchimp, SquareSpace, etc. Make it so you don't need a Developer to send your email, put up a response form, throw up a website.
That though could still be B2D. "Hey Mr Developer we need to do an online questionare. How long would it take you to build something like that?" "Go checkout Wufoo" (out of my hair so I can work on more important stuff)
