Sales Count

I've been looking at displaying product sales counts on the frontend of the store.

As far as I can see the sales count is stored in two different places in the database, and at least on my test site - the two locations don't seem to agree [That could just be a test site issue I guess?]

So - should I be looking at:
- sales_count on the wp_mp_products table
- The post meta WHERE meta_key = 'mp_sales_count'

Which one is right?