Whenever anyone makes a recommendation you have to ask yourself: is this person making this recommendation because they have actually investigated the thing they are recommending and found it to have merit, or are they doing it simply because they are getting some personal benefit from making the recommendation. I hope I don't have to explain why a recommendation has much more value in the former case than the latter.

This may not matter much if the thing you're recommending is an email client. But it matters a lot if the thing you're recommending is, say, an investment in a startup company. It also matters a lot if you're, say, Amazon or Yelp or TripAdvisor and a big part of your stock in trade is an enormous volume of product recommendations.