As someone that currently manages 150+ accounts I regularly come across the same three problems. Below I highlight problems and offer a solution to each.
Remarketing list fails to build up
First check that the remarketing code has actually been implemented on your site correctly. Next check that you are getting traffic to your site. If you are not getting any traffic then your remarketing list won’t build up.You may also find that your remarketing list has been disapproved. This will happen if your industry is one that Google does not allow you to remarket to.
If everything above looks fine then I would recommend creating a different remarketing code to see if that can solve the issue.
If all else fails then start a fresh Adwords account just for remarketing. Sometimes there are issues an Adwords account but creating a new account solves this. Your Search campaigns won’t be affected as you are only running remarketing in your new account and this can save a lot of frustration with remarketing campaigns that don’t launch.
Negative keyword list has reached 10,000
Whilst Google doesn’t let you add more than 10,000 negative keywords to a campaign you can continue to add more by creating a ‘Shared’ Negative keyword list and attaching it to the relevant campaign.
You work in an industry that Google heavily regulates and you want to update your adverts without down time whilst Google review them
Make the changes in a draft campaign and create an ‘experiment’. Google have to review and approve all adverts in a draft campaign anyway before an experiment goes live. Once these have been approved you “apply them” to your new campaign directly from your draft and you won’t come across any down time.