First, that jpg is low res and looks terrible. If you want to put out crap work then that's the look for you i guess. Just looks goofy with crisp vector text then you have this blurry image in the back.
Me, i go to istock and purchase high resolution artwork as needed and add it to the job invoice. That's the right way to do it.
I don't care if the banners going to be used for 1 day or 1 year, Make it look good. It takes the exact same amount of time to print a crappy banner as it does a well proportioned, high resolution banner.
Excuse the harshness i came off with but i just don't see why people put out work just to put out work. I try to make everything count as i want people to come back because the quality of my products are good.