As a business owner, it often isn't clear cut as to what the best forms of advertising and promotion are going to be to attract new customers and to keep existing customers. By no means should any one form of advertising or promotion be the single method for reaching out to new and existing customers. The old adage about 'putting all of your eggs in one basket' certainly applies here.
A website should be thought of as a way to advertise, promote and brand your products, but also as a way to provide supplementary material that you cannot put into your newspaper or directory listing services. For example, you can put URL's into your newspaper ad that might take a customer to a product announcement, a shopping page, an information link, a contact us page, etc.
Similarly, in your directory listing service ad you can put your home page or a link to your Contact Us or About Us page so the person that sees the directory listing ad (especially if they are viewing your ad from a smartphone or their PC), can go directly to your site to get more information.
There are a lot of stats that show that almost 50% of people who look at the Internet Directory Listing Services are most likely to purchase online. So, if your ads have URL Links to your website (or shopping site) then you can be sure to at least get the customer to your site.
Bottom line: continue to use your traditional forms of advertising and then provide additional sources of information or promotional information or direct links to your products and services by adding URL links into your ads (NOTE: Look at using QR codes also as another way to get customers to your website).