There’s money in writing Firefox Extensions, the free add-ons that add new functions and features to the already powerful Firefox Browser. PDF Download is one such example.

When you click some link on a web page that points to a PDF document, the default behavior is that the browser starts to download the PDF file and loads it inside the embedded Adobe Reader. This can sometimes freeze Firefox especially when the PDF is large.

PDF Download extension solved the problem by letting users decide the next action if they accidentally clicked a .pdf link. The extension also offered PDF to HTML conversion very similar to Gmail.

Nitro PDF, who develop a PDF writer similar to Adobe Acrobat, got interested and acquired this Firefox extension because it allowed them reach a very targeted audience who have already expressed their interest in PDFs by downloading the “PDF Download” extension.

The extension remains free and is a recommended download by Mozilla. It has so far been downloaded more than 5.5 million times and is providing more than half a million free PDF-to-HTML conversions per month.

A win-win situation both for end users and Nitro. We may see such a trend catching up in 2008 where product companies grab the popular extensions from respective Firefox developers to make their presence felt in the community.

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