My top performing art asset here gets about 1.5% so I'd say 2% seems insanely good. I'd say anything above 0.5% is doing reasonable.
It’s also important to know the absolute value of impressions. 10% isn’t a lot when you only had ten impressions but one click.
Yeah you should wait for a few thousand impressions at least before jumping to conclusions. If you aren't getting the impressions then you have other issues.
What percentage of those viewing your store page download the asset(s)?
0.9% of viewers paid for my top performing asset.