I would say the line exists when you astroturf. In the case of the restaurant, they're not making up fake customers to fill out the other empty seats. The peop

I would say the line exists when you astroturf. In the case of the restaurant, they're not making up fake customers to fill out the other empty seats. The people who are in there are genuine diners. Invoice numbering is completely arbitrary, but the preceding invoices before the start do not exist. With two-for-one vouchers, the businesses take a hit in the profits; they are giving up something to bring in that extra business. But online businesses and services are astroturfing and no one calls them on it. They're not giving up something to create business. They're not "filling the window seats". They're committing fraud and they know it.