Am I missing something with seller financing

[Barri Griffiths]

I'm currently about to submit an LOI on a property, and want to include seller financing as part of the deal. I plan on asking for 10% of the down payment(the remaining 15% of the 25% down payment would be made by me)at a 5% interest rate, 7yr term, 25 yr am. The only problem is, this severely affects cash flow and the returns.(even though you're required to bring less money to the table) I've always heard that seller financing is like the holy grail, but unless I'm missing something, it seems like you'd need a deal that's a big home run for it to work!?

Am I overlooking something, or is just a case of I will need a better deal for seller financing to work?