Michael Ward, from price comparison website Paying Too Much, claims his research showed much better persistency levels in protection business where the customer chose their product directly through an aggregator site.
He said: "The question is whether persistency rate is linked to the quality of sale made and whether that customer got what they wanted."
But protection experts queried the stats suggesting that IFA sold policies had a much better persistency rate than Ward claimed.
Phil Jeynes, head of account development at PruProtect, said: "We monitor persistency rates very closely as part of our agency control procedure and it isn't fair to say that distinct types of firm fair better than others.
"It is interesting to note that advised intermediaries don't always perform better than their non advised or aggregator counterparts.
"It boils down to the business model of the firm and also how well the sale was positioned with the customer; some intermediaries, advised or not, are better at this than others."
Alan Lakey, principal at Highclere Financial Services, slammed Ward's numbers and said: "I cannot vouch for his figures and would like to know where he obtained them.
"My own protection business has a 97% persistency rate and I know that other protection advisers can show similar percentages.
"My instinctive feeling is that advised sales will always have a better retention rate than aggregator sales. Paying Too Much will have customers whereas I have clients and this is a crucial difference."
Lakey warned that choosing to use an aggregator site is taking a gamble because unless the sale is advised the consumer is not covered by the Financial Ombudsman Service and the customer is making their own choice on "the efficacy of the product for their specific purposes".
He added: "Of course, any quality adviser will always look to see whether he can improve his client's situation by re-broking. This isn't churn. Churn by definition is where a replacement sale is arranged with no benefit to the client."
Roy Mcloughlin, IFA at Master Adviser, said protection business written via IFAs is by definition of "a higher standard than that processed via the mostly non advised bucket shop solutions that others offer".
He said: "This is because thankfully the public both appreciate and seek advice on protection solutions rather than simple and often misinterpreted products.
"The internet provides a very useful research tool in these solutions but ultimately the consumer still yearns for professional and comprehensive advice."
