Put advertisement but make sure that your blog visitor doesn't get irritated when ads pop up one after another like a flood.
Focus on good content, not on monetization. Over time, money and benefits with follow good content.
Avoid using SMS abbreviations in blog post and at least run the post through a spell-check in MS-Word before publishing. If the bloggers cannot take the time out to write proper English, why would the readers bother reading through that cryptic puzzle?