How I increased my email response rates 2-400%!

Hi guys,

I don't post very often as I didn't have much to post about, but now I've started my business properly I've got something I'd like to share. I sell offline services - mobile sites etc, and prospect by email as well as other methods.

Now I'm no copy writer, nor a good written salesman, so I simply have 'Inquiry' as the subject line of my emails, and a 'personal'-sounding email written.

But I found a way which (I may be wrong) doesn't seem to be mentioned here on the offline forum that ALWAYS doubles-quadruples the responses I get, and it's absurdly simple.

I email all the people who didn't reply again, about 4 working days later, a shorter and slightly more salesey email with less of the personal introduction and more of the this will benefit you/your competition are doing it.

Now I'm sure a lot of you guys are already doing this, but to whoever isn't, DO IT! It makes your message seem less like it was thrown out by a random marketing machine (several replies have got back to me starting with 'thanks for your email, I assumed the first one was just a random marketing blast').

If anyone has anything to add to this - perhaps what to include in a follow up message to increase conversions/the subject line (I haven't tested enough to judge the effectiveness of different subject lines), that would be great.

Guy