Apart from working for others we also have our own sites, so we are very interested in conversion rates and how to improve them.
I was very happy these days when, with a small improvement i made to a site, I increased by 3x the CTR for the adsense. That means 3x more money in the bank 🙂
Obviously, I applied the learnings on other sites as well, with the same nice results.
Now I’ll go to clients and tell them: Give me 30% of the extra you will gain based on my optimizations. Win-Win situation, isn’t it? 🙂