LN+ provides a match making service so you can open to other nodes and they open to you. This gives you free incoming liquidity. Doing this also decentralizes the Lightning Network by helping nodes connect to various other nodes besides the top liquidity providers. On long term this will allow us to be more resilient especially if top nodes go down, like Zero Fee Routing's node did recently (top 3 node).

Amboss, Pool an Ads all provide a paid way to get incoming liquidity. So you don't need to open to anyone, nodes open to you for a fee.

Buying inbound lightning channels. Without inbound liquidity you cannot receive payments.