Browser extensions: Total numbers

• The browser extension ecosystem is highly fragmented, in that half of all Chrome extensions have fewer than 16 installs, while 87% of them have less than 1000. Some 10% of extensions have no installs. There are 188,620 extensions available on Chrome, as of last year, so there are a large number of "competitors" with few users each.
• According to Extension Monitor, the total number of installs is at 1.2 billion.
• Some 13 Chrome extensions have at least 10 million installs however. These include Cisco, Google Translate, Avast, Grammarly, Adblock, and Honey.
• The most popular types of extensions /by install) are ad blockers, communications, coupons/shopping, security, and password managers. Productivity apps are the most popular, with 676 million installs.
• FreeAddon is the most popular Chrome extension author (ie company).

Tiers

• On Chrome, extensions are free, or include in-app purchases or in-store purchases. Some 8.9% of extensions and just 2.6% of installs are for the latter two types - ie paid apps.
• The top five paid extensions make up 48.5% of all paid extensions.

Consumers

• A Mozilla survey on extensions/addons found that social proof was important for users when deciding whether to use an extension or not.

Information availability

• Our initial research suggests that while there was one 2-part report conducted on Chrome extensions, there are no such similar reports on Firefox addons. Mozilla's own blog, for example, provides a lot of helpful information on addons, extensions, and developments, but no general stats.
• Market type data and usage statistics that are publically available tend to be broader and focused on browsers generally, rather than specifically on extensions.
• Case studies, research, and reports into browser extensions tend to be focused on the security side for users, and on underhanded data collection by extensions.
• Our early research found that there are no user demographic surveys for extensions, so determining the country breakdown may be difficult. However, the country the app was developed in (the country of the author), or the language apps are provided in, could provide some useful insights.