Based on my own opinion, I can say that the most effective search engine to reach others is Google. I personally use Google all the time. It is easier to use than Bing and yahoo. There are more results that you can find from Google because more people are using Google.
According to my research, the number one search engine that people used worldwide is Google, followed by Bing and the third spot was taken by Yahoo.
From the Comscore report last February 2016, Google got 64% searches wherein Bing only has 21.4%. There is a great difference of 43% between the 2 SEO.
Google is mostly used in laptops, computers, tablets and phones.
If you want to promote your products using these search engine, Google is a very effective way to promote your products or services since it is the largest and the number 1 search engine in the world. Since this is the number one search engine, it is more expensive than Bing. If you want to promote your products and services, you can try Bing ads. It is also helpful in promoting your products and services since this is the 2nd mostly used search engine and the fees are cheaper than Google ads.