Nothing that a startup would say will make me choose their service or product. I will make my decision (as I had all the time) based on the product or service, if it is what I am looking for then I start using it, I don't care if it is from a startup or a well established business.
Trail versions and demos are essential when trying to sell a product or service - IMO.
No one wants a salesman to convince them to purchase anything. A successful sales department in any organization is all about helping potential customers determine if the solution they have is useful enough for them to purchase it.
With this in mind, here's the questions your company has to satisfactorily answer for me:
I think your question is really one you can answer better than me:
To what extent does you being a startup impact my purchase related questions above?
The only thing I really look for is a positive Return on Investment. If you can show me how your product will make me more in return then it costs, and I'm not already using a similar product then I'll purchase it.
For example if you are selling a customer survey app, don't just talk about how it gives the business more data, businesses don't want more data (it's just bloat).
But if you can show how by gathering more data they will be able to tweak their product to appeal more to the target market and thus make more sales then businesses will be happy to purchase your app.
Startups need to have something innovative that solves a problem I have. That's all that's needed. Then I'd buy it.
But not all people will. Conservatives will wait until you change the technology and become one of the main players. They want stability and assurance that you'll be around for awhile.
If I like the product and the cost works well for me, I would give it a try for 30 days (free) and then buy it depending on the experience.
First I want to know that what you're doing is real, and really solves a problem I have. The sales person is the person whose voice I'm least interested in here: I'm interested in the passion your team have for making me happy. (And if you have early customers, hearing their stories could play a big part.)
Now I'm convinced you could help me, the sales person has a valid role in paying attention to my very specific situation - to helping me get value right away, and growing value over time.
And of course, if what you're offering is simple and self-service, with no significant customisation or integration, that role for sales may well be best discharged by technical or other staff - or simply by your focus on product usability.