How to analyse sales data to optimise stock purchasing

To make sure your money is working for you, you need to regularly use the sales reports from your Point of Sale (POS) system. This data is the key to understanding what’s selling well and what’s gathering dust. Use this insight to re-order popular books confidently and reduce spending on stock that isn’t moving, which will directly improve your cash flow and profitability.

Why your sales data is your secret weapon

Guesswork is expensive. Every book on your shelf that doesn't sell is tied-up cash you could be using elsewhere. Analysing your sales data helps you move from guessing what customers want to knowing what they’ve already bought. It allows you to build a bookstore that reflects your customers' actual tastes, leading to less waste, better profits, and happier readers who find what they're looking for.

What to look for in your sales reports

Your POS system can generate several useful reports. Focus on pulling these key pieces of information at least once a month:

• Bestsellers: This is your most obvious report. Which specific books have sold the most copies in the last week or month? These are your reliable winners.
• Slow-sellers: Which books haven't sold a single copy in the last three months? This is your 'dead stock'. Identifying these items is crucial for deciding what not to re-order and when to consider publisher returns.
• Sales by category or genre: Are you selling more crime fiction than sci-fi? Is your children's section outperforming your history section? This helps you understand broader trends within your shop.
• Sales velocity: This is about how quickly an item sells after it arrives. A book you sell out of every week has a high velocity; one that takes six months to sell has a very low velocity.

A simple process for data-driven buying

1. Schedule a regular review: Set aside time every month (or even every fortnight) to look at the data. Consistency is key.
2. Pull the key reports: Generate your bestseller, slow-seller, and sales-by-category reports for the period you're reviewing.
3. Ask 'why?': Look at your top sellers. Why did they do well? Was it a local author, a TikTok trend, a book club choice? For slow sellers, why did they fail? Was the cover unappealing? Was it in the wrong section?
4. Take action: Use your findings to build your next purchase order. Increase quantities of proven sellers and consider trying similar authors or themes. For slow-movers, decide if you need to discount them or process a return.

Data tells you what has already happened; your expertise as a bookseller helps you decide what to do next. Balance the numbers with your own knowledge of the industry and your customers' requests.

By making this a regular part of your business routine, you'll create a virtuous cycle: you'll stock more of what your customers love, they'll buy more, and you'll have better data to make even smarter decisions next time.