Improving Domain to Contact Conversion Rates: Analyzing the Snov.io Integration and Lead List

I'm using the Snov.io integration to go from domains to contacts but I'm getting a hit rate of like 1/20, I assume this is less than to be expected? I can't see anything that I've done wrong in the set up so I assume it must be the lead list? But I've previously used this provider with Snov and returned contacts for 50-60% so I'm not sure whether it's that or if I've set it up wrong