How to acquire customers which are small businesses via internet?

There are a few options for you to consider:

1. SEM (Search Engine Marketing). Run a campaign on Google AdWords using keywords that describe your service as it relates to the problem you are solving for small businesses. Make sure to setup conversion tracking and goals for the relevant metrics (registration, trial, purchase/subscription) and evaluate your keywords against those.

2. Advertising on a networking site like LinkedIn, where you can actually choose audience based on their roles, so your message would be highly targeted. Create a few ads and note which ones are converting better.

3. Don't neglect SEO and optimize your site (about, faq, help, blog) for the content/keywords to help you drive natural traffic to your site. There is plenty of sites/tools/posts on SEO, but here are some actions steps for building links to your site: a) Start a blog where you can discuss the problem you are solving and explain how your service can benefit different type of small businesses, add case studies for your current customers. Here is an example: http://blog.getvero.com/making-email-better-building-the-mixpanel-for-email/ b) look for communities or blogs that have your target audience (like this site!) and contribute with meaningful answers/comments, mentioning your site/service only when applicable of course (don't spam)

If you look around this site, you can probably get a lot more ideas for customer acquisition. I would also recommend reading The Lean Startup http://www.amazon.com/The-Lean-Startup-Eric-Ries/dp/0670921602 as it's a great guide for building a product that customers want and willing to pay for. Good Luck.

Make sure your website is focused on small businesses and their needs. Most consumers don't really care about privacy and what happens to their data. Businesses usually care what you do with their (and especially their customers') data. Promote features that are more business oriented. Think about what your customers would search for on search engines and optimize for those words and phrases.

Try looking at the practices of other companies that market to small businesses. How are they acquiring customers?

For example, here is a video from Gail Goodman, CEO of Constant Contact. She gives examples of specific strategies that her company has used to reach small businesses, as well as advice on how to discover and test strategies of your own.

In my opinion, you should join the enterpreneur organization or small business community. In that community, you may start to find potential customers. And also you may do marketing research what features which actually needed by the small business customers. If you have find the answers, you might offer them your services/products.

I hope this give solutions to your problem