Does This Make Sense To You?

Have a look at a screenshot of my analytics for a mini site I started in April of this year.

I started getting good traffic and then I was hit by a penalty (Fair enough lol) but since then I did absolutely no link building or updating of the site in anyway. Then for some reason I jumped back into the SERPS for a bit as you can see and then I was hit by the penguin 2.1.

Why would I be placed back into the SERPS for abit?

This has happened to me on a few occasions. It depends on the reason why you think you were penalized. Sometimes if you link build,google will take you out the serps if it thinks you are spamming and see what you do next. If you immedietly remove links,it assumes you are manipulating and penalizes your site. Its shit,but thats google for you. If you do nothing,it may then place you back in. It then takes you back out as it finds other links. Thats my understanding of it. Other guys on here will maybe be able to help you further but thats my best guess. On the plus side,when my sites came back,they came back higher up the rankings so its not always a totally bad thing to get taken out then back again

It could have had something to do with user stats like bounce rate and stuff maybe because the bounce rate of this site was pretty high, somewhere over 85% anyway. How was your bounce rate?