Online language will sometimes vary over what you would use in 'real life' (such as offline), especially when it comes to tweeting. And, what might be acceptable to say in your Facebook post, won't likely be acceptable when publishing a blog post. For instance, it's common to use the 'u' for 'you' when tweeting or updating on Facebook. If you did that for a client's article, you would get fired. Just best to avoid abbreviations for words when writing articles, even if they are acceptable or popular in online social media.