(The Attention economy)
In order to avoid spam using memo in micro transaction I suggest a UI change with new account data field recorded on the blockchain.
Users would be able to specify a minimum in STEEM/SBD to get notified of a wallet transfer.
The default could be set at 0.01 SBD, making it cheap for everyone but relatively expensive for a spammer without much to say of value.
Some popular users who are more often transferred funds just to get their attention could set the minimum amount to 1.00 SBD to be notified.
There has been attack in the past of users and there will be more so why not turn this "loophole" into a feature ?
This feature could be implemented right away by any front-ends without any indication of threshold stored on the blockchain.