Link is to an interesting InsightSquared study that may answer the wrong question the wrong way. The question, should your sales person keep calling, should be should your sales person call. Calling or "cold calling" prospects in a social / mobile / connected world is a nonstarter.
Eli Pariser's Filter Bubbles explains why (TED Talk link: http://www.ted.com/talks/eli_pariser_beware_online_filter_bubbles?language=en ). Pariser explains there is NO WAY you can call me cold and win. Most "prospects" are surrounded by a fortress of content, friends and known and trusted resources.
Warm Is Better Than Cold
We don't know what we don't know and we don't care (lol). NO WAY I would suggest a call until your CRM (Customer Relationship Management like SalesForce) system shows and quantifies interest. I would email a prospect relevant information before I would call.
Calling is intimate and presumes a relationship that may not exist yet. I HATE talking on the phone, but I tweet, Scoop and G+ all day long. Interacting with me on any or all of those platforms earns the right to do something I hate (talk to me on the phone). I'm not in the market for enterprise SaaS stuff at the moment, but bet my feelings aren't too far off (since it wasn't all that long ago I managed a large ecommerce website).
Better when your prospects contact you. Contacting you means you are an order of magnitude more likely to "make a sale". Acceptable ways to contact someone cold include:
* Know one of my friends and they suggested contacting me.
* Read something I published and want to follow or add to the post.
* Responding to one of my requests for help on social media.
An example of that last bullet is I'm looking for a place to stay in Columbus, Ohio for several weeks in November. Help with that and I would be glad to listen to a relevant pitch. The most important point is not to be COLD anymore. There is so much information about all of us so easily available build on something shared, known and collaborative.
BUT BE CAREFUL TOO
I'm way to presumptive. I make errors of commission. Each step in a relationship requires time to solidify, improve and strengthen. Hurry = death in a sales call. Leave some openness. Don't worry or hurry and try not to make errors or commission or omission. Easy to write when I am years away from my last "MUST MAKE" sales goal.
The irony of TODAY is to hurry and push will kill you faster than almost anything. To be patient, relevant and invest is the key to long term sales success. Do I miss having quarterly goals hanging over me? Not so much :). M