Browser add-ons (or “extensions”) are something that every consumer of the internet should know about, if they don’t already.  Add-ons allow you to custom tailor your browsing experience to fit your specific needs.  For example, Skype’s Click to Call extension in Firefox allows me to make calls directly from my browser. This isn’t a feature that would make sense for Mozilla to add to Firefox as not every user utilizes Skype, but it saves me a ton of time when speaking with clients.

These useful, time-saving features are why add-ons are typically built; developers design and build products which provides the user some form of inherent benefit.  Being feature-based products, not many add-ons are initially designed to earn revenue.  If a developer’s product becomes incredibly popular, there is more demand for updates and maintenance to the add-on.  At this point, many add-on developers face a problem where the work outpaces their available time.  For developers wishing to make money from their product (and maybe quit their day job while they’re at it), the following add-on monetization models come into play..

The Freemium Model
The word Freemium is a combination of the words “free” and “premium”.  It can most notably be represented by AOL in the early days of the internet when they were giving away CD-ROMs with thousands of free hours of their service.  AOL gave these CDs away in the hopes that once the free hours run out, they could upsell users to a monthly subscription – free to premium.

The freemium model is not very popular among browser add-on developers, as for every paid add-on that is introduced, the market can easily be cannibalized by a completely free version made by a different developer.

The freemium model also introduces design challenges for the add-on developer; deciding what features to make free vs. paid and other development overhead to keep them segregated.  This makes the Freemium model the most difficult to implement of all models here, but also one of the most lucrative when done correctly.

The Donation Model
Possibly the most innocent and user-friendly model of monetization a developer can implement, yet one of the least effective.  The donation model imposes no modifications to the user experience, rather it requests the user make an optional donation.

One neat thing Mozilla is building into their add-ons community is the Firefox Add-Ons Contributions Program.  According to Mozilla, this feature allows developers to request an optional donation for the work they’ve put into their add-on.
With features such as Mozilla’s offering, the Donation model is very simple to implement.  The voluntary nature of the donation, however, makes it the least lucrative method of them all.

The sRS Model
sRS, or sterkly Revenue Suite, is an add-on monetization method which introduces new streams of revenue by enabling the developer to monetize their users through sterkly’s dynamically targeted ads. These revenue streams impose minimal changes to user experience of the add-on and is the easiest to implement of the bunch.

Unlike Freemium, which requires extensive development effort, add-on developers simply insert a snippet of unique Javascript code into their application and they’re ready to start earning revenue.  After implementing, sRS monetizes users by displaying targeted ads as they browse. Options include display ads, text ads and in-text ads.

sRS is truly the most well-balanced monetization solution of the bunch.  It requires little effort to implement (sometimes less than the donation model) and has the highest earned revenue potential.


As you can probably see, there are many factors to weigh in monetizing an add-on; user-experience, revenue potential, ease of implementation, etc.  Developers should inevitably pick what works best for their add-on’s functionality and their user base.

sterkly would like to lend our support to any developers with questions about monetization, whether they’re interested in sterkly or not.  If you’re a developer with questions on monetizing your add-on, drop us a line, we’d love to help you out.