Binding is refers to the meaning of one to one correspondence.For example, email and mobile phone binding, it is to point to this email address and a phone number is one-to-one, one thousand passwords have been changed, the binding mobile phone number can be going back to the ownership of the email.Of course there will be other USES, see your email provider and your agreement shall prevail.

The idea is that, in the pre-Internet days, consumers were pretty much limited (or "bound") to products that they heard about in radio, TV and print advertisements. Nowadays, the Internet provides many ways to learn about products without having to limit oneself to what you learn about through advertising.

In this case, "no longer bound" means "to no longer have to rely on" or "not obligated". If the consumers are bound to advertisers in their search for goods, then it means that they rely on advertisers to tell them what to search for. Hope this helps.

it means consumers "do not need" advertisers. It can also mean "required to use". Hope this helps.