Would prefer greetingscard(s) and don't really value the singular, however I would think that smallad.co.uk could be a real winner if you use or market it properly (even though the plural would be better).
E.g. using it for sub-domains:-
car.smallad.co.uk
electrical.smallad.co.uk
computer.smallad.co.uk and etc
could see it as a major player in a "goods for sale" site generating commissions - similar to the Afternic Bazzar model for domains.