It depends on your business model.
If you are selling a high value, high margin product or service you might not be able to sell more than a few a year and your sales may be sporadic and unpredictable. If this is the case, consider the relationship you are trying to build with potential and past clients. Follow up with personalised cards or send them an e-mail - make sure they know why you are better than the competition.
On the other hand if you are expecting a moderate to significant demand for your product or service (online or offline) and you have had no inquiries, you may have a problem. If you are running an e-commerce business there are only three possible reasons as to why you are not receiving any inquiries:
Whichever the reason (or if you think it might be something else) GOOD LUCK!
...So to answer your question, you shouldn't feel anxious, you should try your best to identify the reason why inquiries have declined.
I worked in a metric-driven and competitive sales organization that has been successful for many years and emulated by a number of competitors. We sold a financial instrument/service.
The probability of closing a prospective client was approximately 1:1000, and the culture was to focus on quantity over quality of clients approached.
In principle, a prospective client was to receive some sort of prompt (email, call, voicemail after working hours, letter, fax, marketing materials etc) every few days. If the client responded positively or negatively, the lead was 'active'. An 'active' lead was 'safe' for 6 months. If a client did not respond and was not prompted within 3 days or if a 'safe' lead was not prompted the day after 6 months, the lead would become 'inactive' and available for any other sales agent to take ownership of the lead.
Agents would organize their pipelines in 3 tiers (top, uninterested, and unqualified) to always monitor the best leads. Of 100-150 'actived' clients in a month, 3-5 progressed to the next sales stage. The typical sales cycle to closure varied. Typically, about 1/3 of closed clients were within the 1st year of initial contact, the remianing 2/3 of closed clients were 3-4 years after initial contact.
From a corporate standpoint intense competition can be a strong short-term motivator, but can be challenging to manage.
From an individual standpoint I think there are 3 important lessons that might be helpful in thinking about your pipeline of clients: prioritize, be proactive and be persistence.