If you do that bot, start with 200 and increment by 100. With such a low volume you’re looking for, I’d just buy them from tapjoy or ayet-studio… In these 5 days that you mentioned you’d get 200 DL with your bot, thats 20$ with the cheapest option from ayet-studio.
Most people don’t think about the time they spend on making an app as money, but I do. If you spend 5 days on app, and you could get 200$ if you worked for someone else, its like spending 200$ on making the app. So, since you’ve paid 200$ already (and you hope that you will get at least this 200$ back, otherwise you would work for someone else, right?), why not put additional 20$ in promotion, that could increase your chances?
Also, keep in mind that it seems Google looks at other factors a lot right now (uninstall rate, how often app is launched / how long is the session etc), so I think boosting the downloads is not good enough. The bot should download the app and launch it few times for few minutes every day, preferably clicking somewhere from time to time (but not on the ads, as that increases the chance to be investigated and banned. Furthermorethe, the ads should not be displayed cause that will lower your ctr and the ad networks won’t like that and will punish you for it). Also, the fake accounts with the only purpose of downloading your apps could get banned eventually, if google notices that.
I’m also afraid I’ll fail to get any downloads with my new project, so I’m planning to spam some related forums and invest 100 - 200$ to get some initial downloads (I think about spending ~50$ on ayet-studio high retention campaign USA (~300 dl) and ~100$ on appbrain targetting USA and maybe other top tier countries too. I consider spending some cash on tapjoy too, its good to have different providers because you can bid lower and get some installs from each of them cheap.
Also, I’ll do some review-exchange here on makingmoneywithandroid to keep the ratings up - I saw 1-stars from Tapjoy users with a comment “Just downloaded to get free gems for game X, I never used this app” - I don’t know how often it happens.
I think I spent like 200 days on this game, so considering my salary, I spent like 12k$ net already (btw, I work on my app over-time, and my employee would gladly pay me 150% for over-time, so if I worked instead of making the app, I’d have 18k$ in my pocket), why not put another 200$ in marketing? The only reason why I won’t put more is that this game’s purpose is to earn some money to promote my second game, which will be upgraded, changed a bit and reskinned first game (reskinning and changing will take like 1 month, but I’ll release it 6 ~ 12 months after the first one).
My advice: forget about the bot as its complicated, against google policy and probably not worth it. Make apps worth downloading, with nice icons, screenshots, description and invest some time and/or resource on marketing.