The service was created in 2011 in the Czech Republic. It is an online forum where the users can share their experience with phone numbers, both annoying (mostly telemarketing, surveys) and useful (e.g. couriers, offices)..
Since the beginning, the service has been received very well, which led to localization into more languages. Nowadays, the forum exists in more than 20 languages and 34 countries throughout the world.
The service is intended for anyone who wants to identify the owner of an unknown phone number. The creators of the forum have also recently created the mobile app Call Insider for Android phones. This app, which is connected to the database of the website reverse-lookup.co.uk, also allows users to automatically block telemarketing numbers.
Said she was calling from a company called Optimiser on behalf of my bank to complete a customer satisfaction survey. I hung up when she started asking for financial information.