Initial communication was via LinkedIn, then I had a phone interview, followed by 3 visits to the office for face-to-face interviews. Then was told that I would hear back the next day. I didn't hear from them for 2.5 weeks. Not professional at all. If you weren't going to call - don't tell me you are. If you don't know an answer the next day - that's understandable - either don't tell me you're going to call or call and tell me you don't have an update. Follow through is critical. I'm selling you on my skills, but you're also selling me on the company. Not a good impression.