What are the average conversion rates for your industry? This marketing research chart from MarketingSherpa will give you reason to cheer or leave you depressed.
If you are in a retail business, you are more interested in the purchase than getting them to subscribe. Non profits have the most difficult time because they don't typically offer value, they are hoping for a donation.
Why professional and financial services are the top on the chart may be directly related to the dedication of professional online agencies.
What this shows that if you are higher than 10% conversions for your landing pages, celebrate.