Sainsbury's Local's don't often recruit due to the sheer number of dual contracts in place - so there's not often a need to recruit any new colleagues, as the current ones shift about that much [I know that in my store, around 60% of the colleagues are students - works perfectly, as when the students leave to go back home, and sales inevitably fall by around 60%, so does the labor costing].
So yeah, its sometimes better to apply for a supermarket and move onto convenience later. Although in convenience, you're expected to know much more. With all due respect to those CSA's that work in supermarkets on specific departments, you guys don't need to know nearly as much as the CSA's that work in the convenience store I have to :P As a team leader, I also have to learn sooo much more. Its worth it though