We don’t have a rule-of-thumb for how many profiles to suppress (by percentage or raw number). Some of our brands are shocked when we recommend suppressing over 50% of their list up front. Others get an initial audit recommendation of 5-10%.
This is all tied to (1) list health and (2) the risk / reward calculation based on the brand’s performance, customer data, and time of year. Brands that start with us in October (or right before whatever their biggest season is, e.g. back-to-school), see that we don’t recommend suppressing many folks, and might recommend reactivating profiles that had previously been “cleaned” from the list, but actually might buy.
If you’ve used deanonymization services, run sweepstakes or done list sharing, purchased a list, etc. you might find a very large, scary number of suppressions at the start. We have a strong perspective on that, and you can read more here!