goodroi - 10:55 am on May 16, 2013 (gmt 0)
Free web hosting has a long history of problems. Some of them have blocked googlebot in the past to save on bandwidth. Other free hosting sites have added hidden links to client sites. Most of the time free web hosting does not have a problem but why risk it. If these sites have real value then you should invest a few dollars for real hosting.
ps I've been using this link tactic in Google for over 10 years, they know about it and have become pretty fast at spotting it and devaluing it. I'm not saying it can't be done just saying most people that do this today are not happy with the results.