Wondering how to rank on Google but unsure where to start? Though there are plenty of easy ways marketers can increase their rankings over time in Google's search engine results page (SERP), you could be making one big mistake that could cause your ranking to plummet: not offering a mobile or responsively designed site. In the past, having a website that was optimized for mobile was a definite plus but didn't have much of an impact on search results and ranking. However, now that we truly live in a mobile-first world, the search landscape has changed, and having a website optimized for mobile is more critical than ever. And here's why.