Google has a lot of reasons why it may punish a website, and why it may punish a blog. These same rules apply to a blogging site that has lots of guest blog posts on it. However, a website with a lot of guest blogs on it may create its own set of problems. Here are a few potential problems that may affect your guest blogging site.
It may turn into an article site
Google may simply start to view your blog as just another article site because people are simply uploading article after article in the same manner that they would on an article site. There is nothing wrong with this, but your website is no-doubt set up like a blog. So, what you are left with is an article site that has a blog structure and blog navigation system, which is hardly ideal. For that reason, Google may decide to punish your website.
If they are poorly maintained
If you are not writing a weekly blog post then you have little incentive to actually maintain your blog very well. If your blog maintenance slips then you may start to be penalized by Google. If you stop caring about blog post quality, or you do not track down your bugs, or do not update your RSS feeds, etc, then your blog is going to fall into disrepair and Google will penalize you for it. Even things such as too many internal broken links or too many links that point to redundant websites are going to get you penalized by Google.
The guest posts are turning more into a link farm
This happens when you stop caring about who uploads what. The point of a blog is to have a series of posts on a certain topic or theme. If your posts do not have a certain topic or theme then you are just setting up another article site. You need to take care with what you allow on your site and what topics people write about. If your blog is just full of mixed articles on a number of subjects, then your blog may appear more like a link farm where people are just uploading for the sake of a link. And, Google does not like link farms and will penalize your website.
Poor quality content is being used on there
The quality of your content should be fairly high and should be consistent. If it is consistently low then Google will penalize you (which is a no brainer), but if you have a reasonably high quality level that only slips upon occasion, then you are in a far better position. If you make a habit of letting poor quality guest posts appear on your blog, then they are going to slowly drag down your blog until Google starts to really penalize it.
Linking to bad sites
Google is happy to tar you with the same brush as the websites that you link to. That is why you should be a little more careful about what links you accept on you blog. Links to sites that have malware are definitely going to get your penalized. As are links to sites that are clearly only there for black-hat SEO reasons. There are probably a bunch of other factors that Google takes into consideration; they are just not letting on as to what they are.
To be on the safe side you should try to link to sites that have no nefarious reasons to exist and to sites that are definitely not breaking the law. All you have to do is check the links that your guest bloggers send with their blog posts.
The content may be over SEOed
If the content is full of keywords or the sentence syntax is messed up because the writer tried to put awkward SEO phrases into the text, then you are going to be penalized by Google. The Google programmers know why your site has funny sentences and phrases and may put up with it to an extent, but if it happens a lot or if a page is particularly bad for it then you are going to be penalized.
The guest blogger may spam links to your content
It is a known fact that Google will punish websites that have spammed links. So, what a naughty guest poster can do it spam links to the guest post. That way the link gets a lot of nice publicity for a month or two until Google punishes the blog itself. Doing this is also a good way of getting rid of the competition too.
About Writer: Kate Funk is a writer and tutor at tutortop.com where she offers different test taking strategies for the students.