Recommended ad platforms:
1) TopWebComics $1 Daily Sponorship. Gets you around 30 clicks a day. Takes minimal effort to establish. Maybe an hour of your time. Contact Marty B. at TWC, give him $30, make your ad box and forward him the image as well as the URL. Do yourself a favor and make that URL into a Bit.ly so you can actually track how many people are clicking the box, otherwise you will never know since Marty does not provide any sort of traffic report. If you like your results then you can buy another month and so forth.
Don't buy their other ad options. You're looking at $.20/click or more.
It's interesting, readers ignore the ad boxes but pay attention to the $1 sponsors.
TWC clicks generate approximately 8 episode reads per click and about a 10% conversion rate into subscribers.
2) Project Wonderful. Can run on any budget. Downside is learning how to set everything up and then create all the bids. About 4 hours of time to learn via trial and error, create the ads, and set up the bids. If you set the bids to never expire then there's not much maintenance time. From time to time we check in to see what ads are not preforming well and if over $.05/click just cancel the bids. We've narrowed it down to about a half dozen well preforming places and just leave the boxes as is. The ads don't always run because they get out bidded half the time but over the long haul they appear often enough and preform well.
Some websites affiliated with Project Wonderful use bots to drive up their traffic so be wary of things that look too good to be true. These bots bring the average read rates down significantly, with about 4 episodes read per click. In general, Project Wonderful clicks result in a very low subscription rate, less than 1%.
3) Google AdWords. The king of clicks. Downside is the platform is terribly unwieldy and takes a MASSIVE amount of time to learn how to use. Call tech support for help? Good luck on that. They will run you in circles and waste your time to no end. You just have to learn via trial and error. The upside is you can get 100s to 1000s, of clicks each day for some of the lowest rates around. We've gotten clicks as low as $.028 that are live readers who read on average 10 episodes per click. AdWords clicks result in about a 5% subscription rate.
Dollars and Sense:
Only advertise with money you can afford to lose. Tapas subscribers only financially support series at about a 2.5% to 3.0% rate. This is comparable with public television and radio support rates. Our numbers are based on analytics from multiple Tapas creator Kickstarter campaigns. The average value across all subscribers is approximately $.50 in gross Kickstarter sales. Note this is GROSS not NET. It costs a lot of money fulfilling all of those rewards. On print copies you're looking at about $.25/subscriber net.
If you are buying clicks for $.05/click and your subscription rate is 5%, then you are buying a subscriber for $1 who on average will buy $.50 of product with a $.25 net revenue, for a total loss of $.75 per subscriber.
Setting Realistic Expectations:
80% of all traditionally published books are financial failures. These 80% authors receive $1,500 to $5,000 advance for a novel that took approximately 400 hours to write and never see another penny. Publishing houses only keep publishing books because 1 in 20 will be a bestseller and carry the other 19, including the 16 duds. Editors keep guessing at what they think might sell well and sometimes it works out. Other times well written books fail and poorly written books succeed. Much of it comes down to execution.
50% of businesses fail in the first 5 years. 60% of restaurants fail in the first three years.
Odds are that your webcomic will fail, at least financially. You would be better off working a minimum wage job if earning money is your #1 goal. If it takes you 10 hours to do one page of a webcomic, then you may be making less than $4/hour.
At the end of the day, only do this if you love it and you are willing to lose everything, both your time and money. Having the appropriate expectations now will save you tons of anguish later.