Uiz.io is a popular url shortener, that is never struggling to monetise its links well, as the owner seems to be an expert with ad networks.
They have been using these ad pages for over 2 months! I think they are here to stay. Uiz says they are trying to be a permanent shortener like ouo.io, adf.ly, linkvertise etc.
They use moneytizer, which pays 70-90 days after the end of the month, but the risk is on him, the owner, but you could still be careful!
Simple earnings - over both pages:
Moneytizer Banners x6 - $1.2 (CPM)
AdsTerra Social Tag x2 - $0.3 (CPM, CPC)
PropellerAds PopUp x3 - $0.8 (CPM)
AdsTerra PopUp x1 - $0.35 (CPM, CPA)
RPM - Earnings from Clicks and CPM in ad networks altogether per 1000 impressions.
CPM - Earnings from just views and no clicks per 1000 impressions
CPC - Earnings for 1 click
CPA - Earnings when someone completes an action such as a signup.