If your speaking about Facebook's API then that the decision on whether to use it is highly dependent on the purpose of your site. Personally, I would think very carefully before branding your site as a Facebook addon. <p>You might be referring to Thrift. In that case, it's only useful if you want to do cross-language services. I don't think an early-stage startup needs this sort of architecture but I guess designing for scale never hurts. <p>
The power of the internet today is the social component. It seems silly to spend resources reinventing the wheel. Does it make sense to use Facebook's developer toolkit?<p>1) Should you worry that you're relying on the infrastructure of another company? Will VCs worry about your long term prospects?<p>2) Would it be ok to use the developer toolkit until your business is a success, and then switch to your own code?
There would be almost nothing in common with your non-FB "toolkit" and the FB one. Theirs is a way to access the FB database, yours wouldn't be. <p>Hopefully you're not imagining that FB for some reason decided to give away the tools that would be needed to create another FB. That's not what they mean by "toolkit".<p>