I have just switched from a hosted to self-hosted WP site (as of yesterday) as I wanted to have a bit more control over what I can and can't do with my site, like being able to use plug-ins.
On 24th April, I noticed that on my hosted (WP.com) site I had started to loose a lot of traffic, which has continued to this day. I did initially believe that my site had been hit by the Penguin update by Google, but have since thought otherwise.
I was advised a couple of weeks ago to NoIndex my Tags as this may actually be the issue with regards Google not ranking my site as high as it previously was. When Googling inurl:http://techfleece.com/tag/ it results in 16,800 results which seems way more than I actually have. I normally have about 5-10 tags per article, but am now thinking that I shouldn't bother with them
I downloaded the Yoast's WordPress SEO last night as this plug-in would allow me to NoIndex Tags. I mainly wanted to see if it made a difference (after leaving it for a while) The thing is though, that even though I have ticked the box next to Tags in Indexation, my site still shows 16,800 results when Googling inurl:http://techfleece.com/tag/
Is this anything to worry about, or am I not giving it enough time?