One site & members area or two?

[Big Daddy]

I have two pay sites with two completely different members areas. One is our amateur site robertacanyon and the other a nitch content site thewebharem. I often wonder if I should join the two together and make one huge site. First I should mention that robertacanyon.com and .net makes far more $ than thewebharem and its seven different guest area doorways that sell it. They both have very good content and lots of it, so it's not as if I need to put them together to make it worth the $19.95 . They both covert well and customers leave satisfied.

Pros of one big site:
1. Only one site and what’s new page to update, add to & manage.
2. More frequent updates.
3. Two sites for the price of one, to advertise to surfers.
4. More content in general to keep our customers busy longer.
5. More focused on one site & more time left on my hands.

Cons of one big site:
1. Possibly more bandwidth usage.
2. Once members move on I'll have no other site to sell to them.
3. Having all my eggs in the same basket.

This might be a dumb question as I think I know the answer is to leave things as they are, two sites to sell. I'm also sure I'm missing some pros & cons. I just had to throw this long time thought to the sharks, just to see what the kind of interesting feedback this question may generate from the experts.

Any feedback or stories will be appreciated!

Big Daddy