as a loanee and a loaner i can tell you this, finding people that are likely to pay back is hard, people will tell u i always pay back and if im late its like 1 day tops, (usually womens fault but yeah) as a loaner the trick if you are after maximum profit is to wait until last minute loanees pop up as they are going to be more willing to pay high levels of interest... as for what interest you charge thats up to you i generally go by how many loans vs how many defaults they have had and how many days they want the loan for, longer the loan higher the interest, not forgetting how many points they want...