An in-demand service that doesn't exist: Paying mortgage/rent with credit cards

Nowadays, I'm surprised when I look for a product online and can't find one. I figure that if there's a service I need, someone has already created the service. It may not be free, but it's almost always out there and available in some form. I'm even more surprised when I find other people online in high-traffic places (like Yahoo! Answers) looking for the same service and it's still not around months after people have been asking about it.

In this case, the service that I and others are looking for is a generic bill payment service. I pay my electric bills, phone bills, etc. with my credit card, partly for convenience and partly for the points/rewards/cashback. However, mortgage companies don't take such payments (I've heard of a couple that do but they're very few and far between. I'm not sure why they don't take them, but I imagine it has something to do with fear of chargebacks? Not sure. You can buy a car with a credit card and that's a much bigger chargeback than $1-2k.

So what's needed here, and what I've been looking for for about 5 years, is a proxy between my credit card and the mortgage companies. Currently, there's a couple ways to do this, but the transaction fees don't make it attractive.

1. Cash Advance: The first way is to do a cash advance on the credit card. Deposit it in your account and then pay your mortgage out of that account. Even with promotional rates, the charge is usually about 3% of the amount of the transaction, often with a $90 ceiling. That's too high to make it worth the points though and you usually don't even get points for this sort of transaction.

2. Paypal: There was a time where I could actually send myself cash in Paypal and they didn't take a fee. I think you could send up to $100 without any fee or something like that...but now, they charge you about 3% for everything and creating two duplicate accounts is a pain.

I've looked for other Paypal-esque services but very few even exist anymore. Most of the smaller ones that are around only offer ACH (checking) drafts...but we want to be able to grab money from the credit card.

There's a number of ways that a company that offered such a proxy could make their money back from the transaction fees. I personally would pay about $5/month for such a service. I would want to be able to add funds from anywhere (checking accounts, credit cards, paypal). I would also want to be able to pay all my bills in one spot. The average user may not even use their credit card in such a service that would generate large transaction fees. The company would be doing bulk transactions so the charges to them would be about 30 cents plus 1.9% for each transaction that they would need to recoup just to break even. I'd be fine paying $5 per month and looking at some ads (if they weren't too obnoxious). The company could also require a minimum balance of a couple hundred dollars (which they would use to make interest collectively to defray costs...ideally this would go with the monthly fee, like most banks work, where I could have a larger monthly minimum balance and not have a monthly fee). I'm sure a number of people would leave their accounts relatively idle as well.

The numbers could definitely work. And the demand for such a service is clear. So someone build it already...