• they are familiar to library staff and managers
• they can be analysed relatively quickly
• information is collected in a standardised way
• they are usually straightforward to analyse
• they overcome the difficulties of encouraging participation by users
• they are often required and respected by decision-makers within the institution and beyond eg funders, government
• they support qualitative data obtained from questionnaires, interviews etc with ‘hard facts’
• they are useful for benchmarking purposes.