Many start ups are great at coding and creating a cool web app, community, tool, etc. but don't want to or don't know how to do everything else necessary. What services would a start up want to be taken care for them?
Accounting and book-keeping, once money starts to flow.<p>Payroll.<p>Support (you'll want it taken care of, but you shouldn't succumb to the impulse--at least not entirely, because you need to support customers daily in order to understand them).<p>Legal crap. Taxes, employment agreements, etc.<p>I want to say billing and invoicing and payment handling, but I think it's probably more efficient to bite the bullet and integrate these tightly into your own system--so that you always know exactly what's happening and how every change in your product or marketing effects your bottom line.
I agree with the others posting here and I'll add PPC ad mgmt . Most startups that I personally know/work with are founded by programmers and designers. Their core business requires focus in those areas yet they spend a lot of time working on PPC/marketing (and often inefficiently).