While I'm not entirely sure what to make of the estimated sales numbers provided, it's certainly worth checking the neat little widget by which Thunder Game Works is tracking the performance of its Trenches iPhone game.

Updated daily, from the start of 2010, it gives the game's range of chart position in terms of the US Top 100, as well as an estimated units sold figure.

However, as even Thunder Game Works points out, the sales estimates at the bottom of the chart are purely estimates. Many factors are used to determine the sales estimates including product refunds and third-party VooDoo.

"This causes the sales calculation to be inherently flawed. While these estimates are not 100% accurate, they do represent a close approximation of total units sales."

For the record, I made the sum of the inherently flawed but close approximation to be 444,276.

[source: Thunder Game Works]