If you are struggling to get business in you may consider stopping or cutting back on your marketing. If you marketing has been set up and managed correctly then it should be improving your sales and enquiries so stopping it is only likely to make things worse. If stopping your marketing does not have a negative effect on your sales then it was not working correctly for you in the first place.
When doing any marketing it is vital that you monitor how successful it is. The advantage of online marketing is it is often easier to monitor and track than offline marketing. If for example you use Pay per Click advertising then you can track how many visitors you get to your site and what they do when on there. You can see if they make a purchase or complete an enquiry form. If you are getting visitors but they are not converting you first need to ensure you are attracting the right people. Make sure that your ads are only showing for products or services that you offer. Within Pay per Click campaigns you can usually set up negative keywords or only show your ad to a certain area which should cut down on the number of wastes clicks your site receives.