Tasked with building an Online Blockchain/Cryptocurrency Community for a Cloud Gaming Blockchain ICO:

• How would you go about building the online community?

I’d build a bounty campaign for different participants to receive tokens at the end of the sale for a % of the tokens, divided into stakes. These people would create, share, push content and traction on all major social channels and wherever they might be an influence (steemit, medium, their own review sites, etc). This includes a VIP program for more stakes for people that we approach and invite (think top Twitch streamers - PewDiePie? :) ). Bounty participants would then pay for their own promotion in crypto spirit of decentralizing the rewards for the efforts of the little guys. This bounty campaign would involve people that would post to forbes, entrepreneur, cointelegraph, etc to boost visibility.

Bounty campaigns can include many aspects, but not limited to:

Translations
Local language moderation
Twitter
Content creation
Signature campaign
Youtube
Telegram

I’d research and identify then approach social influencers who are big in the games or platforms involved, or have a voice in that area (by device, genre, etc.) - either as advisors, bounty participants or straight paid in Eth to mention, review, support the Cloud Gaming Blockchain ICO. Twitch and YouTube would be the focus.
I’d initiate social channels that are moderated and involve the core team members: Telegram, Twitter, Reddit, etc. depending on the level of resources we have available. Telegram and Bitcointalk thread moderation are essential, the rest are ‘bonus.’ The moderation of these channels involves searching for mentions and other content in non-official areas of the social channel so that we can keep our voice over the pulse of communication.
Everyone loves airdrops! I’ve noticed they’re ineffective at getting continued support for ICOs after the signups and etc actions are performed. I’d attempt a tiered airdrop: 1. Tokens for signing up etc tg, reddit, wherever 2. Tokens for referring people 3. Tokens for CONTINUED engagement, on an exponential scale over time. More effort and longer engagement = more rewards.
Depending on the platform itself, I’d reward participants in acting on the platform with a % of the bounty tokens we ‘color’ for use within the platform. If it’s a gaming ICO then I think we could get people to express interest in taking part in social play, tournaments, etc, and so when they actually eventually use the platform a % of their tokens unlock as they engage the platform. These colored tokens work such that they are required to be used by sending it to a tournament address or whatever works within the platform before then being unmarked and anyone can use them for anything. These tokens would make great bonuses on top of the sale stage bonus, competitions, etc.
Competitions for bounty tokens are a great way to engage the community - video contents showing regular contributors theorize on how they’d use the tokens on the platform for a vote to see which are most useful and get a hefty amount of tokens. These videos would then be broadcast across social channels and through the bounty participants for max. visibility
AMA sessions with the core team which are then also pushed on different social platforms throughout dev, ICO, and post-ICO are critical. The more communication from executive team = the more contributions, even if the topics at hand are tricky. Crypto appreciates transparency, and crypto never sleeps :)
If possible, a beta platform for early contributors or bounty participants would be advantageous. If not, a working proof-of-concept (even just screenshots) is needed early in the sales stage process. Ideally, a public beta would be available inbetween pre or private sale and public sale dates (for FOMO)
Well-written whitepaper, well-reviewed public code, solid 24/7 support team are key.

• Explain what channels you will use to build the communities?

Word of mouth (think the bounty campaign might have referral links so that ‘word of mouth’ can be incentavized, ie. your referred traffic and users can earn you % of their contribution)
Social channels (paid CPC and influencer + free-ish fb, twitter, instagram, etc sharing)
Crypto communities (btctalk, subreddits like /r/ethtrader /r/ethinvestor, etc) - paid traffic from etherscan, btctalk, etc.
Gaming-specific communities ie. Twitch. Top console/mobile/whichever platform uses forums, etc (paid, free-ish and free promotion)

• How will you measure the success of your community?

WOW, MOM, etc. Organic # participant growth of official channels, measured and documented

messages. Mentions, comments, likes/favorites, # engagement on places like btctalk, reddit, telegram, as measured and documented (automatic where possible thru existing or custom solutions, or tasked on a weekly basis to mods)

Growth of email subscribers, whitelisters, # double-opt in interactions among analytical data on landing pages, etc. metrics
While the ICO moves through pre-ICO and all stages of sales, $ value contributed