Eloqua campaign to increase subscription renewals.

Do you have any Eloqua campaign strategies and recommendationss to improve the effectiveness of email campaigns with increasing renewal rates & sales, in a B2B2C model?

In our use case, our Eloqua client wants to create a program to increase their renewal rates, and the idea is to keep the customer engaged during the year prior.

I will appreciate it if you could share some examples of before/after, with recommended KPI's & stats.