Digital services Arbitrage, is that a good idea?

So , guys, thinking of starting my own Services Website.
Where I'm gonna be Listing plenty of Services such as
Web Development, Graphic Designs, SEO services etc.
i'm going to outsource from Fiver to Odesk to Other services to Local Freelancers.
I am going to promote my landers with Google adwords. And maybe FB PPC.
What do you guys think. All of your suggestions and Tips would be highly appreciated