Re: Failbook slurping from Tesco Direct
I guess that it allows Tesco to target their advertising. Say you only go to Tesco's (or any other store's) website when you want to do some shopping - you're visiting it on their terms. A retailer will want to tell you about stuff which they think will prompt you to start that transaction and maybe buy something extra, say by telling you about some attractive offer. They can promote that offer through any advertising channel, but directing adverts to known customers, e.g. through Facebook, simply means better rate of return on their advertising spend.