No matter how well your ads, emails and landing pages are performing, they can always be doing better. That little bit of knowledge should eat away at any marketer or business owner worth her salt, and by not striving for constant improvement you're leaving money on the table and letting your competition eat your lunch.
Continuous testing is the only way to ensure that your campaigns are always improving. This means that you should eternally be running multiple variations of everything that matters to your lead funnel. Every email, every PPC ad, and every landing page should always have multiple versions running and you should be in a constant state of analysis and incremental re-factoring.
When you queue up an email to send to your whole list, instead split your list in half and send the same email with two different subject lines, or send emails with two different main offers or calls-to-action. After a few days look at the data and figure out which subject line or CTA produced the best results. In the next email, split your list again and try two different variations of the version that won the last time. Keep doing this every single time you send a message to your list, you have nothing to lose and everything to gain.
Running PPC ads? Each keyword you're bidding on should have at least two different ad variations going at all times. You have 3 lines to vary (4 if you're really creative). Try different approaches in your ad title, or different amounts of keyword repetition in the body of the ad. I've seen some interesting anecdotal evidence that line length and line length patterns can affect CTR rates on PPC ads, for example if your title is short, line 2 long and then line 3 short again, the shape of the ad creates an arrow and can stand out on a high-competition SERP. Get creative and once you see that one of your variations is getting more clicks, turn off the other one and add a new one that varies on the better performing version.
For both email and PPC campaigns, you should be sending visitors to specific landing pages. On a given page there are any number of things you can test, from the number and layout of form elements to the messaging of the copy. Make two or more versions of your landing page and split traffic between the two, eventually you'll see one variation is producing more leads. Turn off the lesser version and iterate on the winner.
If you have a blog or other content pages on your site, you probably have graphic call-to-action elements on your pages (probably in a sidebar). These are perfect for continuous testing and improvement. Run two or more versions of each CTA on your pages and see which produces the most clicks.
By now you should get the point. Everything you do in your marketing campaigns can and should be tested, and not just once. You should always be testing everything, otherwise you're not doing as well as you could be.
How to Generate Leads for Small Business