With nearly half of respondents to a recent survey saying they get more spam now than they did just a month ago, it's not good news that 35 percent of corporate users admit to opening up spam and clicking on a link inside.

It's even worse when it comes to consumers, according to the study from the Radicati Group, a messaging and consulting firm based in Palo Alto, Calif., and Mirapoint, a messaging specialist based in Sunnyvale, Calif. Forty-two percent of consumers say they have clicked on a link in a spam message, potentially downloading viruses, spyware or Trojan horses. At the least, clicking on the link lets spammers know that they have hit upon a working email account, which will keep the spam coming fast and furious.

And the numbers, according to Radicati and Mirapoint analysts, show that to be true.

Talking to users who have clicked on links in spam email, 57 percent of them say they receive more spam now than they did five months ago.

''This preliminary data is surprising and somewhat shocking to us,'' says Marcel Nienhuis, market analyst at the Radicati Group. ''It explains why email security threats, including spam, viruses and phishing scams continue to proliferate. Major advancements in technology approaches that routinely achieve 90 percent plus catch rates are becoming widely available, yet no technology in the world can protect an organization if users exercise bad email behavior.''

Logging into the bad email behavior category goes those users who actually buy into spam's sales pitch.

The study, which surveyed 791 users in March and April of this year, shows that 13 percent of corporate users and 11 percent of consumers say they have bought products and services advertised in spam.

Here are some other interesting notes from the study:

  • Respondents to the survey say 39 percent of the email in their inboxes is spam. For corporate users, that number is slightly lower, coming in at 33 percent. Consumers report the number at 42 percent;
  • Forty-nine percent of both corporate users and consumers say spam has increased in the last six months. Twenty-four percent say it's about the same;
  • They survey shows that 9 percent of corporate users, who tend to rely on email the most, are using email less because of spam;
  • And 10 percent of corporate users say they use the Internet as a whole less because of spam;
  • One-third of users have been dissuaded from communicating online with banks and financial institutions because of spam, phishing attacks and other email scams;
  • The survey also shows that 18 percent of users reported receiving IM spam, or Spim, in the last three months.