Will Google "punish" my website for advertising my other websites?

Somewhere a while ago, I read that Google punishes websites that are caught with malicious "link exchange" or something of that sort. I suppose that means if a person pays you money to leave a permanent link to his website on your sidebar, that would count as an violation of their rules, right?

Well, I was thinking, to get a bit more traffic to my other blogs that are all very similar, I should put up a widget on my sidebar with the title "The ##### network" and display the rest of my 3 blogs there.

Will this trigger the Google violation detector and punish my website by removing it from the search engine?

 

This is perfectly fine if you use a NOFOLLOW link. Otherwise don't!

 

I would like to share a very relavent experience.
Last month i was penalized by google and i got a message in the webmaster tools about suspected link sale.
I had one of my own website linking from one of my other with do follow atrivute. In my reconsideration request i explained in detail that i own both the sites and requested them to check the whois info.
Google revoked the penalty in their reply without any further investifation. The whole process took 13 days and it took another few days for my site to fully restore.
On the other hand if you place a no follow link then there is no issue and u dont need to worry about google.