Why my guest post doesn't appear in SimplexDesign

In SimplexDesign blog, I always welcome bloggers who want to contribute content and giving value to readers . Guest blogger can place two links in the bio as an exchange to his contribution . When site grows , I receive more and more guest posting proposal everyday. But it doesn't mean all guest posts I received are good enough to publish. In this post, I will show you what need to do to make me publish your guest post :

1, Quality of content

It's the first thing that I concern when receive a guest post . As mentioned above, I only receive posts that give value to readers. It means readers must feel that they see something new after reading post. Content must be original and unique, and people can apply to their blog.
Many guest blogger sent me posts so simple that we can find out in internet thousand posts with the same content just by a click. For example a post name 'SEO techniques' is about using H1 tag, title, meta tag ... Or another post name 'Social marketing technique' focus on how to register Twitter /Facebook and create a fanpage only.
Don't misunderstood my words, content in the posts above are not wrong, but I think none of you visit SimplexDesign for a thing like this.

2, Pay attention to the guest posting rules

In my blog ,there's a page name 'write for us' in the top navigation bar . This page show guest posting rules, niche topics, link, bio and email address that you can send post to. For saving times, please don't send me posts on other niches, for example: education, real estate ...They can be published in somewhere else, but not my blog.
Take your time in reading guest posting rules, I think it will easier for you and me. As a blog owner, I feel ok with guest posting proposals that already know what niche topics to write. And I think other blog owners who accept guest posting are the same to me.

3, Take care of the biography 

All I want for a good biography at the end of guest post is basic information on guest blogger, and links to his/her profile or website.
Don't use this for advertisements, don't use this to write something that not about you. It will increase the opportunity your post appear in my blog.

4, Considering link building strategy before submitting guest post

I know many blogger who want to increase ranks, so he/she hire ghost blogger submit guest posts with back links to everywhere. But Google has changed their policy and some blogs got penalties from Google for their back links.
Several days ago, I have to remove back links in a guest post as request of a webmaster. He hired link building service submit guest posts to many sites, even unrelated sites, afterthat, his website has been moved to Google sandbox.

Guest blogging bring benefit to both of guest bloggers and blog owner. I'm not an expert that know and write everything. So I need contribution from you all. Knowledge is for sharing.
If you follow all things above, I think your post will appear in my blog soon.