Different business segments have distinct preferences when it comes to banks, according to the latest DBM Consultants Business Financial Services Monitor.ANZ was popular with micro businesses (sales revenue up to A$1 million dollars a year) in DBM's March 2014 survey, which gave it equal top ranking with Commonwealth Bank. However, ANZ ranked last among small, medium and large businesses.Commonwealth was well ahead of its peers in the estimation of large businesses (turnover of $50 million and above) but came back of the pack in the ratings of other segments. Large businesses gave it a rating of 7.8 - the highest rating of any bank in any segment.National Australia Bank rated poorly with micro businesses, which gave it a score of 6.9 out of 10. NAB was not a standout performer in any segment but its best ratings were among large and medium businesses (turnover of $5 million up to $50 million), which gave it a rating of 7.4. Small businesses (turnover of $1 million to $5 million) gave it a rating of 7.3.Westpac was the top-rated bank among small businesses, which gave it a rating of 7.5. Among the other segments, it came back of the pack.Micro and small business tended to give lower ratings than the ratings of medium and large businesses, which is probably a reflection of how the banks allocate relationship managers and other services.