Yes, UnityAds works great with just 3 actions from LampRabbit:
http://hutonggames.com/playmakerforum/index.php?topic=8311.0AdColony should not be more difficult either, to get working.
But UnityAds is often not enough:
- you should be using both, or more, as there is nothing more annoying when you offer your players/users some ads to watch for ingame stuff, but don't have any ads to show,
- UnityAds only advertises games and for example a lifestyle app should get much higher click through rate from AdColony ads targeted for that specific audience.
Example: your grandma won't get excited about a Clash of Clans ad, but will click Oprah Winfrey's new cookbook ad.