Paid Registrations XF2.2 Activity Summary Email: include link to account upgrade.

Now that XF 2.2. has Activity Summary Email functionality, it's also possible to insert addon content into it. It would be very valuable to promote Paid Upgrades to the member base. This can be done in the same way as the available upgrades are displayed on account/upgrades

Upgrade Now.
Only today from $9 for $5

That would generate some nice income.