The results are in. This was probably the most successful Humble Bundle to date, based on the ending average price. Let's look at the data for the Average Price over Time.
|Average Price over Time|
|Total Purchases over Time|
|Total Revenue over Time|
As you can see from the graph. At no point did the average price go down much at all (there were a few times it went down a penny or two). This answers the question I was initially asking, at least for this bundle: should I wait for a lower price? The answer is of course emphatically no. If I was going to beat the average price, the time to do it was as early as possible.
I do seem to recall bundle average prices going down in past bundles, but this may have been due to abuse by people pumping the system for free and/or very cheap Steam keys. That practice seems to have been cracked down upon with CAPTCHAs (remember: only use your scripting powers for good), and the momentum of the price and interest in the bundle seems to have been maintained by the addition of the bonus content. I would expect similar measures in the future.
As it turned out, I when the extra bonus content was added, it was also added to the account of everyone who had previously purchased the bundle, whether they beat the average or not, so I ended up with all but the initial two bonus books.
These marginal rates were all calculated from the previous values. It would be interesting to have better data at the beginning of the data set. I'm curious to know how the profile of the initial wave compares to the second bump. You can't really tell with the first seven hours missing, unfortunately. My suspicion is that the secondary bump was sharper than the initial wave, mostly because I believe that the secondary wave was largely fence-sitters who had not bought because they thought the price was too high for the content offered. When more content was offered (and considering the content), they immediately jumped on it.
|Marginal Purchases (every 15 minutes)|
|Marginal Revenue (every 15 minutes)|
|Marginal Average Price (every 15 minutes)|
If you would like to look at my raw data, I will provide it for download in its unprocessed CSV format generated by my script, as well as the Excel spreadsheet that I used to calculate the missing values and create these fancy graphs.
Here is the data: