In this chapter, we'll look at a strategic application of webbots—monitoring online prices. There are many reasons one would do this. For example, a webbot might monitor prices for these purposes:
Notifying someone (via email or text message) when a price drops below a preset threshold
Predicting price trends by performing statistical analysis on price histories
Establishing your company's prices by studying what the competition charges for similar items
Regardless of your reasons to monitor prices, the one thing that all of these strategies have in common is that they all download web pages containing prices and then identify and parse the data.
In this chapter, I will describe methods for monitoring online ...