Write a 1000-word article in fluent Swedish with the title: Varför det är viktigt att använda A/B testing vid annonsering. The article should be written naturally, be engaging and easy to read. Only use H2 and, if needed, H3 headers in the article. The headers should have the correct html tag. Include a list in the article if possible without affecting the quality of the article. You are writing for my website seogruppen.se. My company is SEO Gruppen. However, don’t make the article too ”selly”, the purpose of this article is to be informative. For conclusion, don’t use the word ”Slutsats” or ”konklusjon” – Use ”Sammanfattning” or ”Sammanfattningsvis”. PLEASE REMEMBER TO WRITE MINIMUM 1000 words.