While the Internet and text messaging has made society more tolerant towards spelling and grammatical mistakes, that doesn't mean all standards have disappeared. When it comes to building credibility, correct usage remains important.
Here’s a report from the BBC that demonstrates how poor spelling can cost businesses credibility--and money. One company found that sales doubled after a spelling mistake was corrected on its website. Read about it at http://www.bbc.co.uk/news/education-14130854.