Encouraging competition within your sales team or showing partiality when dealing with issues can destroy your team. You must find ways to encourage them to work like a family. Setting a target for the whole team and rewarding them equally can encourage love and unity which in turn will cause the sales people to encourage and help one another as they work hard to achieve one common goal.
Would you as parent encourage your children to compete and try to beat each other at pleasing you. I personally think that you will sow seeds of jealousy and hatred within your family if you ever do that.
Recognition of best performance is significant but I think it must be done carefully without destroying the unity and the love that binds them team together.