Keeping income on your blog coming in constantly can be a stressful task, there are three things that advertisers are looking for in a blog to buy ad space.
Content Quality and Relevancy
Keeping content quality up can be hard because of several writer blocks and personal matters that keep popping up at the wrong time so it’s better to write as many articles as you can at once and save them in your blog for future use. This helps you keep your post/day rate up in case you hit any writer blocks.
Mostly it’s the content that sells your ads, the more informative and well written your articles are the more ads you’ll end up selling. Having other bloggers on your blog as well might be a bad sign for advertisers because they are buying ad space so that they can beenfit from your (the owner)’s articles, not other bloggers. Try to refrain from having alot of people blog there really soon.
Traffic - Feed Readers
Every advertiser looks for feed readers as the main selling point, the more feed readers the more advertisers you’ll attract, for the people who don’t have many feed readers and are still working on them to grow, I’d suggest to get more traffic to substitute for feed readers.
A few days ago the folks at 45n5 made a blog sell out report, it had a long list of money making blogs and the max price they sell out for and it was based on feed readers, every reader was worth $18
Authority
When I say authority here it means more then having niche authority, it also means having more backlinks a stronger pagerank, great serps and more.
The more you promote your blog via seo or other networking methods the better, the more your blog is seen in the similar niche circles and heighborhoods the more advertisers will lean towards you. This can also mean using adwords to get more popularity or buying reviews from bigger blogs. Promotion non the less.



