Re: Value for money??
"I had a friend who advertised a new product through fb with particular demographics specified. They got increased sales from the campaign and given that it was pretty much their only marketing, its reasonably safe to say it worked."
It says nothing of the sort. You say "advertised a new product" which strongly implies that you changed the bleeding product on offer to punters! It is hard to imagine a more significant variable to change prior to hunting for a change in sales figures.