From my background in software and services sales, I've seen many situations where "being inside" provides a terrific opportunity. Congratulations on winning the right to walk inside!
Now that you're there you need to do three things, the first wo of which are more-or-less obvious: (1) deliver on the KPIs and any tacit outcomes as well; (2) manage the process well, i.e. to reduce friction and daily hassle and lastly (3) be seen to be doing these things.
This last item is sometimes missed by business or technical professionals in any field. To explore the question in more detail it's important to know the business you are in, what you are supplying, and what your customer's real needs are. (It appears to be a B2C play.)
So, to do job, to do the job well, and to be seen to be doing the job, you should consider that you are always "on".
In sales we say you "have two ears and one mouth, use them in that ratio". In other words, do lots of listening. What do your partner's KPIs mean? You could nail the KPI and then discover that the customer made a mistake! So do a SWOT analysis (or any preferred business model analysis) of your customer's evolving situation.
Especially, how are you bringing value beyond the initial engagement? You have won a coveted spot by being great. Now is the time to make sure you don't hide your light. Bring more value. This opportunity sounds like a major step up for your company, so it makes sense to master the opportunity and to grow the relationship beyond the current specification.
Proofs-of-concept and pilots and indeed any renewable service relationship are always opportunities to shine. If you'd like to chat, I'm especially interested to know your business sector.
A big success for you and your team!