We produce mobile applications for businesses of all sizes. In the past, the majority of our clients have been big names: Guinness, Universal Pictures, Ernst & Young, etc.
As we reformat our website, we're trying to determine how highlighting those clients will affect our ability to attract small businesses and startups. Will potential clients typically read it as "oh these guys are way too big and expensive" or "Oh, I know those names--if the big guys trust them, maybe I should check them out."
So: Will it evoke confidence or intimidation?
Davey, In my experience it evokes confidence. But here is a better way to find out. Run an A/B testing and see how your site visitors convert. Check the user flow and see what they do next.
If you want to highlight the vast range of clients, or even size of clients, to indicate your reasonability, I would explicitly highlight that. I am by no means a web designer, but I would go with something along the lines of:
We have the resources to provide professional mobile applications for companies such as Microsoft, Guinness, and even Universal Pictures. We are also personal and affordable enough to work with small businesses such as Harry's Auto, Mike's Pizzas, and OneStopPetShop, just to name a few.
You could put there logos in, instead of the names, and have the logos link to the website of the companies (free publicity for them!).
To answer one of your questions, some will inevitably think you are too big and expensive, but if your whole site design says personable, down-to-earth company, you shouldn't have much to worry about. This means getting rid of the generic corporate images that we see time and time again, and go with something more realistic to your company.
I thought this was a good example, I have no affiliation but I can say that they seem like a small enough company (they have a picture of what appears to be their whole staff, or probably the full timers anyway) that I was surprised to see they worked on the app for Dominos, because I had already used that app and it is AWESOME. Personable website, big clients. It can be done.