I use Google AdSense and I'm worried that I might be punished using traffic exchange services like MGID, Scribol, Crowd Ignite, etc...and if this will affect my site's SEO.
Does Google frown upon these services?
I did a quick look at the sites you mentioned.
Avoid link exchanges. Period. Scribe Ignite looks like a link exchange.
I am not sure who your audience is. If your site is small or new, then I would focus on your own content and marketing it on your own for a while.
Scribol: I guess it depends on the kink of content you have. I cannot recommend this service unless your content falls within the more timely popular topics such as celebrity, sports, film, music, etc. Scribol works where if 4 users are driven to Scribol, then 4 users will be driven back and you will need 4. That means you need traffic to start.
MGID looks somewhat the same however instead of a 1 to 1 ratio, MGID promises %160. Both require that cooperating sites install a widget. I cannot tell you how well this works. I have net ever been compelled to click on one of these widgets and I have not seen any of these widgets on any professional sites yet.
But traffic should not be the only goal. You will need to know how to market your own content and become comfortable doing so. Rely on this first. You only need to Google Scribol Spam or MGID Spam to see any issues there are.
If you are advertising with Google or other advertiser, you will need to check with them to see if these services violates policies. The short answer is, Google may not like it. This may be considered a link or content exchange.