Cold calling not effective so far

Today I continued the project of trying to get more customers for a software product of mine. I have not met with as much success as I had hoped:

• One company on my list doesn't even use the necessary companion product despite being listed on that product's web site as a long-time user
• Another is actually out of business, despite being listed on the web site
• One answered the phone, I asked to speak with the person who I had already e-mailed, but he was unavailable, so the phone answerer took a message, but the person I was trying to reach has not responded in any way

I have yet to expand into non-already-emailed potential customers. Hopefully those future attempts will go better.