I'd like to build a website similar to those listed above: One that searches forums and other sites for watches/jewelry by keyword & price. I assume the software to search the listings has already been built, so my questions are as follows:
Which API are these sites using to scrape their data?
Is there a different API that you would recommend be used for an aggregate search service such as this?
Can I use this API to expand the search listings beyond forums to eBay, Chrono24, and random jewelry sites?