A tale of two sales

We hold a sale every three months. We take all the boxes of clearance books from the shed and put them on display. They are five bucks each or five for ten dollars. A steal. Between times we funnel good books that won't fit on the shelves into the clearance boxes and move on the less good ones, in preparation for the next sale.

We had a sale on a super stormy Saturday July 22. And we had another one this past weekend, a rain-early-but-then-clearing Saturday October 28.

The table below compares numbers from the two days.

July 22 October 28
Sales transactions 110 55
Books sold 357 246
Revenue $2,155 $1,135
Facebook reach 13,789 3,696
People who said they were interested 352 181
People who said they were coming 67 23

You can see that in July we had twice as many sales and made just under twice as much revenue as the October sale.

One reason why might be that the Facebook advertising in July had much greater reach than October. We spent $15 in July and twice that last month. The advertising was essentially identical. So something happened in July that caused people to share it much more than in October.

The graph below shows some metrics derived from the sales numbers above.

You can see that:

  • We made less revenue per book but we moved more books per sale (four and a half books per person is a lot: the average in ordinary time is around two). This indicates that we sold relatively more clearance books and fewer full-priced books in the October sale.

  • We also had a higher revenue per sale overall in October. Combined with the large number of books per sale, this says to me that the sale worked, i.e., the very cheap books encouraged people to spend more than they otherwise would. It might also mean that our clearance books were better quality this time around. We certainly had more books (52 boxes compared with about 40) and they were better arranged inside the store.

  • And perhaps we had fewer people show up who are more inclined to buy full priced books. One influence could have been greater competition as a result of it also being National Bookshop Day, which meant that there were lots of other book-related things for book-keen people to do on that day.

Business is a constant process of theorising about ultimate causes while blundering around trying to plug the obvious holes. In summary, we know that:

  • Something good happened with the Facebook ad in July that did not happen in October.

  • The better weather in October did not obviously help (maybe terribly stormy weather in July made bookshopping more appealing).

  • We had more people inclined to buy clearance books in October than July.

  • And even at half the size of the July version, overall the sale was a success, bringing in about five days' revenue in one day.

The next sale will be on Saturday January 27 next year. Adding another data point to the series will doubtless help in generating more hypotheses, if nothing else.