Sorry for the n00b question. Trying to wrap my head around how to set up % metrics. I have stated (data from BigQuery):

SELECT
2  mparticleuserid as user_id,
3  eventtimestamp as timestamp,
4FROM
5  `***.mparticle.raw_ecomm_ecommerceaddtocart*`
6GROUP BY
7  user_id, timestamp

As Binomial with Users (counting with binomial SQL the amount of users) as Denominator However the conversion over time in data preview doesn't show a % but something that looks like a count of absolute numbers. What do I need to do to create metrics that calculate the conversion ration?

I think you've probably set it up correctly. I think the main problem is that in the Data Preview, we don't know the total number of users overall in your app to act as the denominator. However, if you add this binomial to an experiment, we will use the number of users in an experimental variation as the denominator, since we can count those using the experiment assignment tables.