What is a good benchmark for a download conversion rate? In other words, what % of my website traffic can I expect to click "Sign Up Now" button to start a plug-in download (examples: xobni.com and tripware.com)? Thanks!!
Sometimes questions have no answers...
It can vary literally by 10x depending on the market, product, customer type.
Also it depends on your traffic source. Traffic from a good review? Should be high sign-up rate because they already understand you and are probably coming specifically to sign up. Traffic from adwords? Probably sucks. Traffic from StumbleUpon? A rate of 0.01% might be reasonable (no joke).
Obviously this depends on a whole lot of factors - what you're selling, how qualified the traffic is, quality of your landing page / web page, etc. etc. But in general terms, the benchmarks I've seen say that it's 1 - 3% for a paid service and 15 - 30% to sign up for free.
It will be interesting to see what others say.
Best of luck!