Make sure you don't have any money in your Outscraper wallet before you add the AppSumo code, because they'll just use your existing balance instead of the deal credits.

Here's what happened to me: I had positive funds sitting in my wallet, then I redeemed the AppSumo lifetime deal. I figured I'd be fine just using the map scraper and email/contact tools that come with the LTD, but nope. They kept charging my wallet for everything. My balance even went negative!

I didn't realize what was happening until I checked later and saw I was at -$13. The thing is, AppSumo only adds their credits at the end of the 30-day period, so there was no way for me to use features like the email validator without my positive wallet balance getting completely drained first.

Bottom line: Zero out your wallet before activating the AppSumo code, or you'll end up paying with your own money while waiting for AppSumo to add the deal credits after 30 days.