The notion of looking for a needle in a haystack comes to life when you try to look for a tweet you saw a week later. This is especially harder if you have a lot of followers and are also following a lot of people. Some eventually give up. Twitter likes however make everything easier. You timeline may have a lot of traffic that could bar you from ever finding the tweet especially if you did not catch the name of the account it was tweeted from.
This is where the usefulness of Twitter likes is evidenced. Once you like a tweet, it gets stored under the likes tab. This makes it easy to look for the tweet when you need to revisit it later. Most tweets may not seem very important but there are some that have useful information you may need. You can thus use the likes as a bookmark. You do not need to remember who sent the tweet or when you saw it as all you have to do is go to the likes tab and check.