When operating in the B2B landscape, it's pretty common. Large corporations take time from the first pitch until signature (sometimes >6 months), and during tha

When operating in the B2B landscape, it's pretty common. Large corporations take time from the first pitch until signature (sometimes >6 months), and during that time you can iterate over concepts based on their feedback. If you are realistic when estimating the probability of signing the deal and thus realistic of taking the risk, negotiate the payment terms wisely (e.g. 50% after signature, 25% on delivery, 25% on acceptance) and manage to survive until first payment, it can be a great approach for boot-strapping. It helps having a reputation at the first clients beforehand (e.g. due to free-lancing for them, or being introduced by others), otherwise large corporations might have doubts working with a start-up anyways. It worked well for my start-up, where I felt uncomfortable with that approach also as a first-time founder (it's pretty awkward sitting there and listen to your sales guy promising what-not to the client when nothing is there in fact), but I've learned a lot from him since then :)