Looking For Thoughts on Small Business Roll-ups

All, I'm thinking about drastically changing my previous search fund plan. I think what I'd like to do is buy much smaller businesses (sub $1M in profitability). Probably ecommerce, given its portability and ease of management. I have seen firms of this type plateau simply because the founder does not know how to put systems in place. The idea (which is not particularly original) is to buy these type of firms, introduce systems and a growth strategy then sell in a higher market. Then wash rinse repeat, same concept as flipping houses, the hold time would be relatively short. Has anyone ever done anything like this? Are there specific investors that have an apatite for this kind of strategy?