Yes, you're right on. But in those 5.2 million sessions there's everything, including the many applications that use our embeddable editors free of charge.
So, it's a cool metric, but it doesn't tell the complete story.
Actual monthly ARPA at BEE is around $27 for our BEE Pro product (hosted email & page design suite) and over $600 for our BEE Plugin offering (embeddable email, landing page & popup builder).