Services-for-equity could be a solid option to minimize overhead for a pre-revenue business, however, giving out any ownership in your business is an endeavor that should never be taken lightly...regardless of the transaction dynamic. Make sure the service is something your business absolutely requires, and make sure you have a solid valuation in place so that you're not giving out free equity to somebody who's unlikely to provide any further value beyond their trade. Make sure that there are contracts in place that outline his/her terms of stock ownership. Treat the transaction as if you're working with a VC.
With the entrepreneurs I've worked with, I've seen these types of transactions be extremely beneficial. I've also seen them end badly. The ones with a happy ending, the entrepreneurs knew the value of their company as a whole, the value of the service to their company at that time, and the value of the service, out of context, in terms of a dollar amount. Given the factors, they were able to assign a fair share of ownership over to their service providers, with a solid contract in place to protect them.
If you'd like some more information on how to coordinate this type of agreement, or if you'd like further advice, I'd be happy to have a call with you. Otherwise, I hope this helps.