New buyer on Fiverr

[chaitanya_k]

Guys, I am a new buyer and need help with some of the features. I am not able to find the help satisfactorily on the help pages, so need help from some of the experienced ones among you.



I have posted my gig and already 13 sellers have shown their interest. I have a few questions on my mind,

1. When do I pay the sellers, immediately while purchasing the services or after the services are delivered to me satisfactorily? If after the delivery, how long is the credit period?
   
2. Do I have a right to reject a service if it does not match the quality criteria?
   
3. I may need to get an agreement signed from the sellers and may want to pay them more than $5, or offer a percentage in campaign. Can I do this?