This was the largest Airdrop I ever participated in: I received 2000 TRX/Tron as an Airdrop from Bit-Z Exchange back in late November/ early December 2017, I believe it was. It was part of a marketing plan to draw in new accounts and was a limited time event.
I was a little skeptical at first, but the coins appeared in my exchange wallet right after I signed up for a new account with them and got verified. I was really excited about it, especially after reading the whitepaper for the project. Even more so when it made such widespread news and became a really popular coin! Unfortunately, I was new to using exchanges at the time & didn't withdraw it to my own wallet right away. (Stupid, I KNOW) Now I don't know if I can because of all the regulatory changes.
They are still in the exchange account, so technically I can still access them... I need to get on that.
Things change so fast in the crypto world. I should have taken them out right away. I'll attempt it and update this post regarding the outcome.
I take part in airdrops sometimes, but only after doing at least some research on the project & conditions now. Most that I find are legit, but some of them are either worthless or worse, an attempt to scam people by getting you to verify with your phone number, which can easily turn into a phishing scam. I stay away from those. Also, many use Google Docs, which is fine, but make SURE you're signed into your gmail account online BEFORE signing up. If you sign in through the doc, you're giving them access to your gmail account (ie, everything on you're drive & computer and/or phone) via your password. There are many genuine airdrops out there that can turn into something worthwhile. In fact, some are already well known coins. Do your research.
Most are part of the marketing budget to draw more awareness to a project. Many projects can develop into something great and make it worth your time. Most "real" airdrops require very little time or effort: just sign up with name, email address, wallet address & join their Telegram channel
*, follow & retweet the pinned message on Twitter. Some require that you Like them on Facebook. Some require that you verify your email. It's a pretty simple process. You also receive a referral code to give out & can easily earn more coins this way. Another plus is that 99% of them are ERC20 compliant (use the Ethereum platform), so you can easily just use your MEW, Mist, Parity, Eidoo, Enjin or any other ERC20 wallet to receive the coins. (
*Note: you have to stay in the Telegram Channel for the duration of the ICO to be eligible for the drop.)
I've seen a shift a little while ago into "bounty projects", where you can sign up & get as many referrals (people/friends/followers) to join using your link. Bounties require a little more work and some active participation but you can accumulate a LOT of coins this way, if you have a medium to large following or can get many friends to join. Also, a good source for legit airdrops is AirdropAlert.com Happy hunting
Edit: Also wanted to mention- (Sorry to those that this is obvious to): The majority of airdropped coins may only be worth between $5 to $50. Some as much as a few hundred dollars upon launch. BUT- If the project is solid and you're patient, they can become worth a LOT more over time if you just HOLD them until it's developed into something strong & gains in value!