see ethereum/EIPs#20 (comment)

Hello,

Currently, I am developing a Free-to-play game
is it possible to get Brave/BAT advertisement network in my game
to show ads to the players and get rewards in crypto

The BAT testnet token sale uses the Ropsten testnet, which is extremely slow right now due to DoS attacks and mining spam. Transactions routinely take days to clear, and it is therefore difficult to both receive Ropsten faucet ether, and also to spend it.

A better testnet to use and advertise on the website would be Rinkeby, for both funders and the contract devs to test out the contract in advance of the real sale on Wednesday.

I've deployed BAToken.sol here on Rinkeby, to end at block 280741 (about one day from the create date of this issue). Anyone is free to use for testing:

https://rinkeby.etherscan.io/address/0x6f036e95c0503f3456059b8a6ec5c81a6d7bfdfa

This line of the token creation function creates tokens at the specified exchange rate when users pay into the contract.
https://github.com/brave-intl/basic-attention-token-crowdsale/blob/master/contracts/BAToken.sol#L55

The comment where the exchange rate is declared implies that 1 ether should get 8000 BATs.

I've deployed this contract to Rinkeby here:
https://rinkeby.etherscan.io/address/0x6f036e95c0503f3456059b8a6ec5c81a6d7bfdfa

and tested it with these geth commands.

> batokenInstance.ethFundDeposit()
"0x83fa180e1557b6598b15d2de154bbef657f8fafe"
> batokenInstance.batFundDeposit()
"0x83fa180e1557b6598b15d2de154bbef657f8fafe"
> batokenInstance.createTokens({from: eth.coinbase, value: 1})
"0xcd053194880ff6f6ab1ab8af85eaffbe858fe948a7cca88f1f86c1fdaa0180c7"
> batokenInstance.balanceOf(eth.coinbase)
8000

After paying in 1 wei, I get 8000 BATs, which is not the intended amount.
For 1 wei, I should get 8000 / 10e18 BATs, which would be rounded down to 0 since the variable balances is a map of address to type unit256.

https://medium.com/@AttentionToken/bat-funding-increase-and-smart-contracts-928d1dbee27e states:

The number of crowdsale tokens is increasing to 1 billion from 700 million, an increase of nearly 43%.

how does that align with the code?

uint256 public constant tokenCreationMin = 750 million

A concern for the logic here

https://github.com/brave-intl/basic-attention-token-crowdsale/blob/master/contracts/BAToken.sol#L70

In a scenario where potentially you get close to the tokenCreationCap and no transaction with the exact remaining value is submitted, the sale will fail and you won't be able to finalize.

like this:
function () payable { //call create tokens }

else branch in line 58 of BATToken.sol is not needed, as if-branch throws and ends execution. Consider moving the else branch outside of the if-else.

    uint256 public constant batFund = 500 * (10**6) * 10**decimals;   // 500m BAT reserved for Brave Intl use
    uint256 public constant tokenExchangeRate = 5500; // 5500 BAT tokens per 1 ETH: THIS MAY CHANGE AT DEPLOY TIME
    uint256 public constant tokenCreationCap =  1500 * (10**6) * 10**decimals; 
    uint256 public constant tokenCreationMin =  750 * (10**6) * 10**decimals; 

Consider capitalizing constants to improve readability when they are used.

http://solidity.readthedocs.io/en/develop/style-guide.html#constants

Constants should be named with all capital letters with underscores separating words. (for example:MAX_BLOCKS)

(This would also be more in line with conventions in other languages.)

Is it closed-source?