Frequently Asked Questions
- Why create priceTrackr?
- Why are there holes for some dates in the charts?
- How should the charts be interpreted?
- How is the daily drops page sorted?
- What does priceTrackr use to make the awesome charts?
priceTrackr was created so that one can make a more informed decision before purchasing items on Newegg.
Holes can appear in a chart for a few reasons. A crawl of Newegg may not have occurred on that date, an error may have occurred while crawling a specific item, or an item was placed in a deactivated state on Newegg. Except for in the case of a deactivated item, it should be pretty easy to extrapolate what the prices on the missing dates were.
Each chart has four lines. The first line, "original", is the price one of the item in the absence of savings, rebates and shipping. The second line, "+ savings", is the price after Newegg's instant savings on the item. This is the cost to purchase the item, when not considering the cost of shipping. The third line, "+ rebates", is the previous price with any rebates also added on. The final line, "original + shipping", allows one to track the variance in shipping over time with respect to the original price.
The best way to look at the specific pieces is to compare them to the other lines. When "+ savings" differs from the original, then at that point in time there was savings on the item. Likewise when "+ rebates" differs from "+ savings" there was rebates on the item.
The reason for comparing the shipping to the original price, rather than to tack on after the rebates price is that the original price varries much less than the rebates price, therefore it is simpler to monitor variations in the shipping price as is.
The daily drops page is sorted in descending order based on the computed drop score each item receives. The drop score is computed by taking the cost drop of an item (yesterday's price - today's price) and multiplying that with the percent drop of an item (cost drop / yesterday's price).
priceTrackr uses XML/SWF Charts version 4.7 to make the awesome charts.