I've tried them a few times and frankly they were pretty bad. Any advice? Someone told me to mix in a little beef burger.

Can't help, never tried it. Way to expensive for me. I do think you would have to add some fat. It (from what I read) is a very lean meat. So to me that says dry. Fat rules for flavor. CF:)

Some would say: "Whats the point". It cost more and seems most are trying to make it taste better by adding beef. I use venison quite a bit and ground it can be used on any recipe that calls for ground beef with the exception of burgers. Previously frozen meat has a hard time holding it's shape in a burger pattie so a lot of folks just go 50/50 with beef when doing burgers. I'm sure bison is much the same way. But as CF said it's more expensive so just buy the beef.