I would like to review one of the mystery to prevent ads limit from coming to your Adsense account. Adsense place ads limit on your account when they find abnormality on your account.
For Example: you are having 1,000 daily traffic before you started using Adsense, immediately you start using Adsense, your traffic moved to 4,000. Adsense will suspect your account. They will suspect that you might have paid to get bot traffic, so they will palce ads limit on your account. This is one of the main area many people fall victim of ads limit. Even though many people worked hard using social media to promote their contents. But because of the sudden massive increase of traffic, adsense will place ads limit. Please check: How to Remove Ads Limit From your Google Adsense Account Under 7 Days.
Please before you place adsense code on your site, check your statistics. Check if your traffic is align, and when you place the ads code on your site make sure you maintain the level of traffic you been having for some days. After like 4 days, then you can do other promotions. I tell you, adsense will not place ads limit again.
Secondly, incase adsense just removed ads limit from your account, don’t place too much ads yet for some days, place like two ads for like 4days before you add more. If not adsense might bring ads limit again.