A good wholesaler will bring a great deal to another investor. To be a good wholesaler though you need to know the markets,negotiate well with sellers and buyers and spot a good deal from a mile away. Problem is as Jeff stated there are those who don't bring anything to the table.
To be a good wholesaler you need to:
1.Do due diligence. You need to do as much due diligence as possible.
2.Evaluate the deal as thorough as possible. Which means finding out what the market is like,what the ARV is and what the estimated repairs are. This separates the men from the boys.
3.Negotiate with sellers and buyers. Your negotiation skills need to be spot on if you want to not only get a good deal going but to sell a good deal to buyers as well.
4.Be a good marketer. Which mean not only marketing your deals online but offline as possible. Combine online and offline marketing is key to be a successful wholesaler.
If you can master those aspects than you can succeed in wholesaling and you can build a reputation that will help you your business in the long run.
And that's what separates good wholesalers from bad ones.