The traffic source translated into Russian is the platform on which the arbitrageur places advertisements. The question is popular and there can be no single correct answer to it, but it is still quite realistic to make recommendations:
• Do not start with dying sources. These include Vkontakte, Odnoklassniki, myTarget. The first reason is that these sources are suitable exclusively for the RU and CIS markets, when you can unscrew traffic around the world in the same Facebook. The second is hackneyed. If you visit the Odnoklassniki feeds or “Vkontakte", probably met offers to buy a miracle fishing rod or light pencils. This advertisement is just launched by arbitrageurs - most often in the negative or with minimal profit.
• Do not go into the wilds. This applies to Google Ads, LinkedIn, YAN and the like. To work with these sources, you need a huge amount of experience and knowledge that no infobusinessman will sell. Don't waste your money.
• The best source is international. To date, these are Facebook and PUSH notifications. All you need to get started is to learn how to target in the FB advertising cabinet or build push buttons in any advertising network. You can work with any GEO and pour traffic even on white, even on gray.

Of course, later the arbitrageur will need Facebook accounts (they are mercilessly banned), skills in collecting white and black lists, but, for example, you can set up advertising for a white offer right away.