I recently wrote an article about why you aren't growing through conversion rate optimisation. If you're exploring the strategy and practicing the concept of conversion rate optimisation, here might be a few reasons why you're not growing.
1. You’re only testing tweaks
2. Lack of genuine user insight
3. Poor quality hypothesis
4. Lack of methodology
5. The majority of the investment is in the tool
6. Silo testing where 2 + 2 = 3
The full article can be found at Formisimo http://www.formisimo.com/blog/why-you-arent-growing-through-cro/