How can we get more sales from enterprise companies?

So, you’re a start-up but you have a full suite of BI tools now. Since you can handle all BI needs, I assume a) you can work with a variety of warehouses and marts including structured, unstructured, location and raw data and b) offer ad hoc analysis, querying, reporting, data visualization and dashboards. You may have tools, or at least some experience, with mobile and real-time BI, data mining and predictive analytics. You’ll need two sales decks. The “long” deck must a) explain who you are and what you offer, b) describe how you implement and support your tools/services, c) prove you can do what you say and d) explain your fee structure and the benefits of your BI tools to your prospect. Your challenge is to convince skeptical prospects that you’ll generate a positive ROI with real world examples. The short deck is based on the long deck: it can be read in two minutes and gets you in the door for face to face meetings. A comparison of your BI tools vs. well known competitors should be included in some versions of the short and long decks. Your proof (c above) is a demonstration with case studies – they will garner most of the prospect’s attention in the face to face meetings. Devote most of these meeting to the case studies. You’ll need sales, operational and financial data, and perhaps industry data, from two or better yet three companies for the case studies. The data must be at scale. A sales demonstration based on sample data will not convince skeptical VPs of Technology that you can handle their data. Creating powerful case studies takes time but it’s doable. Approach previous employers, former clients, companies owned by one of your investors or companies that you know need BI tools. Offer free services in exchange for data if necessary. Offer to anonymize the data and only use it for sales purposes. Each case study in your sales presentation should include examples of how your BI tools identify top or bottom line improvement opportunities. The case studies must knock the prospect’s socks off. Your price (or pricing structure) should include a promise to deliver X times the price in top or bottom line improvements within Y period. I would be happy to help you create the sales deck, particularly the case studies which are so critical to your success, and a pricing strategy.

I'm going to assume you're a small group of people with experience working with BI tools, both proprietary and open-source.
First thing is to understand who your target companies are. For some reason you mention companies that currently have no BI (I'm again assuming you have a good reason for this). That's a good starting point, but not enough. You should at least segment down to industry/sector, eventually region as well. Then you'll choose 1 or 2 sectors to focus on and do research on problems/opportunities within those. This information is key to approach the companies with relevant information.
Then, you need to identify the decision makers within the companies you're targeting and prepare your pitch deck based on the industry/sector information you gathered before, along with a delivery plan and, most importantly, how much your enterprise customer can gain with that.

It's especially important to understand your customer's pains and gains, and that involves getting specific information about their business. I worked within BI in several industries, so if you need some more advice on that feel free to get in touch.

Pitching a BI solution to companies with no BI means you will usually have to "educate" them as to the needs and benefits of using BI. It seems obvious to you, but they have gotten along without it for this long.

Think of your prospects on three levels:
1 - The Client is the organizational client. As others have already stated do a bit more work to define the size, industry, revenue size and location of these corporates.
2 - The Buyer: this is the person in the company who will make the decision. With Enterprise you are selling to a group of people, identify the key driver and build a relationship with that person. Ask a lot of questions about the company's strategic goals and his/her own responsibilities internally.
3 - The End User: the buyer is usually utilizing your BI solution (or maintaining the relationship with your agency) for the benefit of their own internal client, the front office. Know who your buyer is serving.

Example:
Client - Law Firms
Buyer - Chief Knowledge Officer or Practice Administrator
End Client - Attorneys