Top definition
an online advertising technique in which a page or email contains an image that is specifically tailored to your message. when the advertiser sees that your personal image has been requested by your computer, the advertiser knows you opened the page. then your email address becomes more valuable, because it's been confirmed as a real person.
the "increase cock size!!" spam had two web bugs in it, but I didn't see them because I don't use Microsoft Outlook
by claire danes July 05, 2003
Mug icon

The Urban Dictionary Mug

One side has the word, one side has the definition. Microwave and dishwasher safe. Lotsa space for your liquids.

Buy the mug