Shelby got a royalty payment for each Tiger sold.
Tigers were fast (for the price). The 260 V8 made good power, but the Shelby Mustangs had about twice the power, and all of the Mustang's performance tricks worked equally well on the Tiger!
The Tiger did well in the 1965 Monte Carlo Rally.
The Tiger Mk II used the larger 289 cu. in. V8, had 36 more horsepower, and new trim. Only about 500 were made, making these cars very sought after
Another ad with Carroll Shelby.
Indeed, the police in England used the Sunbeam Tiger.
Okay, this is not period advertising, but a 1/64 scale Sunbeam Tiger that I keep on the desk at work.

Mine will look something like this, but it will have nicer wheels and interior, and it will be a lot more fun!