If a company or individual posting to craigslist is having trouble with competitors, fake posts, harassment, etc., there are a number of ways to get things done. I'm sure that Craigslist, like every other site, makes people jump over a few hurdles before they can get in touch with a live human.
Calories Burned. On average, a 150-pound person burns 91 calories biking for 20 minutes at a leisurely pace of less than 10 miles per hour, according to the Calorie Control Council's Get Moving Calculator. The caloric burn increases to 136 calories when intensity escalates to a moderate pace, 12 to 13.9 miles per hour.
The website notes a vigorous, 45-minute workout on the exercise bike will burn 774 calories -- the same as the elliptical trainer. The extra calorie burn from the elliptical trainer is due to the use of your arms, which are largely stationary during an exercise bike workout.